COFFEY, J.
This is a review of a decision of the court of appeals reversing a circuit court judgment convicting Reyes Barrera, Jr., of party to the crime of first-degree murder and armed robbery, contrary to secs. 940.01, 943.32(2) and 939.05, Stats. After the jury trial the defendant was ordered committed to a term of life imprisonment on the murder charge and a consecutive sentence not to exceed 20 years for the armed robbery.
This action arose out of an armed robbery at the Park Avenue Liquor Store in Beaver Dam, Wisconsin, on October 15, 1976. The owner of the liquor store, Mrs. Janis Bussie, was shot and killed during the course of the robbery.
The facts adduced at trial establish that the defendant and his friend, Frederico Garcia, left Adrian, Michigan, on October 13, 1976, to travel to San Antonio, Texas, with a total of $80 between them to be used for traveling expenses. The two stopped en route in Beaver Dam, Wisconsin, to visit the defendant’s brother, Eduardo Barrera, on October 14, 1976. The defendant’s brother accepted their invitation to accompany them on their trip to Texas. On the morning of October 15, 1976, the men stopped [273]*273at the Park Avenue Liquor Store where the defendant and Garcia each stole a bottle of wine.
The three men then drove into the countryside to test shells in Garcia’s sawed-off shotgun. Garcia testified to a conversation with Barrera at about this time in which the defendant stated he was going to rob the lady in the liquor store if she was alone. Shortly before noon, the trio returned to the Park Avenue Liquor Store.
Barrera drove to the back of the store and told his brother to keep the car door open and to start the engine when he returned. He put the gun under his coat and went into the store. He returned to the car shortly thereafter, cocked the shotgun and expended a spent shell in the car. Garcia testified that the defendant appeared shaken as he drove off at a high rate of speed.
Next Barrera stopped the car at a gas station in Hori-con, Wisconsin, and, according to Garcia, announced that he would rob the woman attendant if she were alone. She was not alone, and thus no robbery took place. Shortly after they left Horicon, Garcia testified that the defendant told them that he had shot the proprietor of the liquor store in Beaver Dam as she reached for a telephone.
Garcia then related that the defendant became extremely angry in Missouri when a gas station attendant spilled some gasoline on the ground and declared that someone was going to pay for the attendant’s mistake. Shortly thereafter, when they stopped at another gas station in Marston, Missouri, the defendant robbed, shot and killed another woman, attendant Kathy Evans, approximately twelve hours after the killing in Beaver Dam.
Garcia, although previously advised not to refer to his polygraph examination by the prosecutor made reference to a “lie test” in explaining the circumstances surrounding his decision to testify for the state and against Bar[274]*274rera. The defense then moved for a mistrial in the absence of the jury, claiming that Garcia’s remark about a “lie test” was prejudicial. The court denied the defendant’s motion and in the absence of a request by Barrera, did not sua sponte give a cautionary instruction.
The defendant, when testifying at the trial, stated that the shooting of Mrs. Bussie in Beaver Dam was accidental and further denied any involvement in the Missouri killing. He said that when pointing the gun at Mrs. Bussie (Beaver Dam) he was nervous and trembling because he was “coming off this heroin” and that when he reached for the money, Mrs. Bussie grabbed the gun, causing it to fire accidentally during the ensuing struggle.
Garcia and the defendant were charged with party to the crime of first-degree murder and armed robbery, arrested in Texas by F.B.I. agents under the unlawful flight statute, 18 U.S.C.A., §1073, and subsequently brought back to Wisconsin to stand trial.1
On April 5, 1977, a Goodehild pre-trial hearing was held to determine the admissibility of the defendant’s statements to Robert Anderson, the polygraph examiner and certain law enforcement officials. At this hearing, the defense counsel stipulated to the voluntariness and admissibility of all statements given to Anderson. The statements to Mr. Anderson were obtained during two attempted but unsatisfactory polygraph examinations, on March 7 and March 17, and a pretest interview on April 4, 1977. In the conversation on April 4 the defendant admitted shooting Mrs. Bussie in Beaver Dam and Kathy Evans in Missouri.
At trial, however, defense counsel reversed his posi-sition and challenged the voluntariness of the statements and moved to suppress the April 4 statement. The trial [275]*275court conducted a second Goodchild hearing outside the presence of the jury and reviewed a tape recording of the April 4 interview and ruled that the defendant’s statements to Anderson were admissible.
After the jury trial, a judgment of conviction was entered on April 19, 1977. A motion for a new trial was heard and denied, and Barrera filed a writ of error to review the judgment of conviction. The court of appeals reversed the circuit court and remanded the case for a new trial. The state petitioned this court to review the appellate court’s decision.
Issues
1. Did the trial court commit reversible error in admitting alleged prejudicial evidence of another crime?
2. Was Barrera’s confession to Robert Anderson, the polygraph examiner, during the pretest interview on April 4, 1977, admissible in the absence of a Stanislaw-ski2 stipulation?
3. Was the trial court in error in ruling that the defendant’s confession to Robert Anderson was voluntary?
4. Did the trial court commit reversible error in failing to give sua sponte a cautionary instruction to the jury in the absence of a request for the same after the witness, Garcia, made reference to a lie test?3
Other Crimes Evidence
Prior to trial, the prosecutor informed the court and the defense counsel that he intended to offer testimony [276]*276of the Missouri incident, the second killing and robbery, for the purpose of showing intent and absence of mistake or accident in the killing of Mrs. Bussie in Beaver Dam. Before trial, the prosecutor made an offer of proof in this regard and asked the court for a ruling on admissibility after he advised the court he intended to make reference to the Missouri slaying in his opening statement. In his offer of proof the prosecutor stated that Garcia would testify that on their way to Texas the three men stopped at a filling station in Marston, Missouri, where the defendant robbed, shot and killed the female attendant within 12 hours after the killing in Beaver Dam. He also stated that Mr. Anderson would testify that the defendant admitted to the slaying of the two women, one in Wisconsin and the other in Missouri.
Defense counsel objected to the introduction of the evidence of the Missouri killing on the grounds that the danger of unfair prejudice in its admission would substantially outweigh its probative value. The court noted in its decision that the defendant’s objection required it to balance the alleged prejudicial effect of this testimony against its probative value and ruled this evidence “is admissible under the circumstances of which the court is aware at this time and the court is making this determination, not at the time the evidence is introduced, but at the request of the attorneys because the attorneys are about to give opening statements to the jury, and it is bom out of necessity here that the court give an indication of its ruling and viewpoint concerning such evidence on the trial.” Further, the court informed the defense counsel that he could renew his objection when the testimony was offered into evidence.
At trial, Frederico Garcia related the events leading up to the killing of the service station attendant in Missouri. Garcia testified in part that Barrera went into the gas station with the shotgun tucked close to his body and [277]*277underneath his coat and shot and killed the woman attendant as she stepped back away from the cash register after handing him the money.
Robert Anderson, the next witness called to the stand, testified that Barrera admitted the Bussie killing as well as robbing and killing a service station attendant in Missouri with the same shotgun, some 12 hours later.
At trial the defense counsel did not object to this testimony of Garcia and Anderson, nor did he challenge the admissibility of this evidence in his motion for a new trial.
The court of appeals noted that although counsel’s objection to receipt of the evidence of the Missouri robbery and killing had not been renewed at trial or raised as a ground for relief in the trial court by motion for a new trial, the court, on its own, exercised its discretionary authority to review the claimed error. It concluded that the evidence of the Missouri killing was not relevant, and that even if relevant, its probative value was outweighed by the danger of undue prejudice. On review in this court, the defendant reiterates the decision of the court of appeals.
This court has set forth the rules governing the admissibility of “other crimes evidence” many times. See: e.g., Vanlue v. State, 96 Wis.2d 81, 291 N.W.2d 467 (1980) ; Hammen v. State, 87 Wis.2d 791, 275 N.W.2d 709 (1979) ; McClelland v. State, 84 Wis.2d 145, 267 N.W.2d 843 (1978). Wisconsin’s leading case dealing with other crimes evidence is Whitty v. State, 34 Wis.2d 278, 149 N.W.2d 557 (1967) cert. den. 390 U.S. 959. This court in Whitty adopted what has come to be known as the two-pronged test for determining the admissibility of other crimes evidence. First, the party seeking to introduce this evidence must demonstrate that it is not being offered for the sole purpose of showing that the defendant had a disposition to commit the crime. Ham-[278]*278men, supra at 798; McClelland, supra at 156. That is to say, other crimes evidence may be admissible if it is probative of intent, identity, or an element of the specific crime charged and this probative value outweighs its prejudicial effect. Whitty, supra at 292. This rule has been enacted as sec. 904.04 (2) of the Wisconsin Rules of Evidence:
“(2) Other crimes, wrongs, or acts. Evidence of other crimes, wrongs, or acts is not admissible to prove the character of a person in order to show that he acted in conformity therewith. This subsection does not exclude the evidence when offered for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident.”
The relevancy of evidence regarding other criminal conduct “depends in part upon its nearness in time, place and circumstances to the alleged crime or element sought to be proved.” (Emphasis supplied.) Whitty, supra at 294.
However, after determining the question of relevancy as to motive, opportunity, intent, etc., the trial court must also consider “whether the prejudice of other crimes evidence is so great as compared with its relevancy and the necessity for its admission in the particular case as to require its exclusion.” Whitty, supra at 295. Sec. 904.-03, Stats.4 The decision to admit or exclude relevant other crimes evidence after the trial court has engaged in the requisite weighing process to determine whether the probative value of the evidence is outweighed by its [279]*279prejudicial effect is a discretionary function of the trial court, Vanlue, supra; McClelland, supra; Hough v. State, 70 Wis.2d 807, 235 N.W.2d 534 (1975); State v. Hutnik, 39 Wis.2d 754, 159 N.W.2d 733 (1968), and the question on appeal:
. . is not whether this court, ruling initially on the admissibility of the evidence, would have permitted it to come in, but whether the trial court exercised its discretion in accordance with accepted legal standards and in accordance with the facts of record. McCleary v. State, 49 Wis.2d 263, 182 N.W.2d 512 (1971). The test is not whether this court agrees with the ruling of the trial court, but whether appropriate discretion was in fact exercised.” State v. Wollman, 86 Wis.2d 459, 464, 273 N.W.2d 225 (1979).
Thus, according to Whitty, we must first determine whether the evidence of the circumstances surrounding the killing of the service station attendant in Missouri is relevant to motive, opportunity, intent, etc. The grounds offered in support of admission of this evidence was that it was probative of the defendant’s intent, plan and lack of accident in the killing of Mrs. Bussie. The appellate court held that the Missouri slaying was too remote in time and space to have this effect, in spite of the fact that it occurred only 12 hours later (time) on the same trip to Texas (space, event) and that the defendant and his companions were short of funds (intent).
Relevant evidence is defined in sec. 904.01, Stats., as follows:
“ ‘Relevant evidence’ means evidence having any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.”
In Hicks v. State, 47 Wis.2d 38, 43, 176 N.W.2d 386 (1970), this court, quoting from 1 Wharton’s, Anderson, [280]*280Criminal Evidence (12th ed.) p. 284-87, sec. 148, set forth the definition of relevancy:
“ ‘ “Evidence is relevant when it is persuasive or indicative that a fact in controversy did or did not exist because the conclusion in question may be logically inferred from the evidence. The criterion of relevancy is whether or not the evidence adduced tends to cast any light upon the subject of the inquiry. Evidence of any fact is admissible as relevant which might establish the hypothesis of innocence, or show the defendant’s guilt. Any evidence that assists in getting at the truth of the issue is relevant; in other words, any fact which tends to prove a material issue is relevant, even though it is only a link in the chain of facts which must he proved to make the proposition at issue appear more or less prohable. Relevancy is not determined by resemblance to, but by the connection with, other facts.” (emphasis supplied.)’ ”
Moreover, this court has stated:
“ ‘In proof of criminal intent, the conduct of a defendant on other occasions closely connected in point of time and plan may at times be relevant to throw light on the defendant’s motives and intentions while doing the act complained of. Smith v. State, 195 Wis. 555, 560, 218 N.W. 822; State v. Meating, 202 Wis. 47, 50, 231 N.W. 263. “The intention with which a particular act is done often constitutes the burden of the inquiry, and to prove the intent it becomes necessary, in many instances, to extend the examination beyond the particular transaction concerning which the accused is upon trial. For the purpose, therefore, of proving intent, not of proving the act itself, it is often permissible to show other criminal transactions of the same sort springing from like mental conditions.” 2 Jones, Evidence (2d ed.), p. 1161, sec. 624.’ ” (Emphasis supplied.) State v. Hutnik, supra at 761-62.
The record clearly demonstrates that the evidence objected to passes the first prong of the Whitty test and was properly admissible under sec. 904.04(2), Stats., as [281]*281it is probative of intent, the distinguishing element of the crime of first degree murder from other degrees of manslaughter. The Missouri slaying occurred only 12 hours after the shooting of Mrs. Bussie in Beaver Dam and the defendant used the same modus operandi, i.e., the same shotgun, the victims were females and alone and Barrera initially concealed the weapon under his coat. Thus, the evidence of the shooting in Missouri was relevant to show that both slayings sprang from like mental conditions. State v. Hutnik, supra. Moreover, the evidence was of consequence to the determination of plan or scheme. Simpson v. State, 83 Wis.2d 494, 510, 266 N.W.2d 270 (1978). Therefore, we hold that the appellate court erred in ruling that the testimony regarding the shooting in Missouri was irrelevant.
Turning to the requirement that the trial court must weigh the probative value of other crimes evidence against the prejudicial effect of its admission, we initially note that the defendant failed to object at trial to the testimony relating the killing in Missouri. Rather, defense counsel’s only objection to this evidence on the ground of undue prejudice was made in a motion in limine and not renewed at trial.
This court has stated that a trial judge has no obligation to exclude evidence on the ground of undue prejudice when the objector fails to make the proper motion at trial. McClelland, supra at 158. See also: State v. Starwicki, 93 Wis.2d 63, 74-75, 286 N.W.2d 612 (Ct. App. 1979). Hence, on the question of receiving evidence of other crimes dealing with the issue of probative value versus prejudicial error, we hold that the failure of the defendant to raise this objection at trial and in his motion for a new trial in the absence of constitutional dimensions bars the defendant from predicating error on the failure of the trial court to balance these considera[282]*282tions. Moreover, we note that the trial court, in its ruling’ on the motion in limine made an initial determination that the probative value of the testimony regarding the killing in Missouri outweighed its prejudicial effect. This court will uphold a discretionary decision of the trial court to admit other crimes evidence if the record supports that decision. Vanlue v. State, supra at 92; Hammen v. State, supra at 800. Thus, we conclude on the record in this case there was no abuse of discretion on the part of the trial court in finding that the probative value of the evidence concerning the Missouri killing outweighed any possible prejudicial effect. In this regard, we note that the record fails to reflect that the appellate court reviewed the trial court’s exercise of discretion in admitting this evidence. Rather, the court of appeals made its own conclusion that the probative value of this evidence would be outweighed by its inflammatory nature. In so doing, the appellate court usurped the function of the trial court. We caution the appellate court against taking on the role of the trier of fact. See, e.g., Wurtz v. Fleischman, 97 Wis.2d 100, 293 N.W.2d 155 (1980).
Absence of a Stanislawski Stipulation
In State v. Stanislawski, 62 Wis.2d 730, 742, 216 N.W. 2d 8 (1974), this court .set out the written stipulation standard for admission of polygraph tests and a polygraph examiner’s interpretation of the same in the following language:
“As to polygraph tests taken by the defendant and expert testimony related thereto, polygraph testimony is admissible in this state, as in Arizona under Valdez ‘. . . to corroborate other evidence of a defendant’s participation in the crime charged,’ and, Tf he takes the stand such evidence is admissible to corroborate or impeach his own testimony.’ The required preconditions or quali[283]*283fications for the admission of such testimony, in this state as in Arizona under Valdez, are as follows:
“(1) That the district attorney, defendant and his counsel all sign a written stipulation providing for the defendant’s submission to the test and for the subsequent admission at trial of the graphs, and the examiner’s opinion thereon on behalf of either defendant or the state.”
After his arrest, Barrera submitted to a polygraph examination with the consent of his attorneys. However, it was understood that the results of the polygraph test would not be admissible as the parties had not signed a written stipulation providing for the same as set out in Stanislawski. As noted earlier, the defendant was examined by Robert Anderson of the State Crime Lab on March 7 and again on March 17, 1977. However, Anderson determined that due to Barrera’s anxiety ratio, he was unable to reach any definitive conclusions regarding the results of these tests. After advising the defendant and his attorneys of this fact, Barrera agreed to submit to a third test on April 4, 1977. On this date Anderson conducted a pretest interview of the defendant, his usual procedure in preparation for a polygraph examination. During the course of this interview, Barrera admitted the Beaver Dam and Missouri murders. At trial, and at the time of the hearing on the motion for a new trial, the defendant failed to claim that his statement to Anderson on April 4th was inadmissible for want of a Stanislawski stipulation. Rather, the Stanislawski issue was raised for the first time in the court of appeals. As pointed out earlier, the appellate court reached the stipulation question on its own because it felt that the issue of the admissibility of Barrera’s statement to Robert Anderson on April 4, 1977 “is likely to arise at retrial if not disposed of here.” It held that the defendant’s April 4th statement was inadmissible under [284]*284their interpretation of the logic and holding of State v. Schlise, 86 Wis.2d 26, 271 N.W.2d 619 (1978).
In Schlise, supra, this court stated that the Stanislaw-ski written stipulation rule applied to information elicited in a “post-mechanical interview” and thus in the absence of a written stipulation, statements made by an examinee during post-examination questioning were held inadmissible.
Schlise was an appeal of the conviction of Donald Schlise as party to the crime of first degree murder. The charges arose out of the killing of Donald’s wife, Irene Schlise. The defendant submitted to a polygraph examination and confessed to the examiner, Robert Anderson, during the course of the post-test interview. In this interview, Anderson persuaded Schlise to talk about the death of his wife and confronted the defendant with the test results he had just received every time he suspected Schlise was not telling the truth. The court quoted the following example of the type of questioning Anderson engaged in:
“ ‘The first chart, right, we concluded basically four things. OK. Number one, you did ask someone to kill your wife, OK, we concluded that. We also concluded that you hired someone to harm her. Ok, this is sort of a secondary relevant issue concerned with the set up. And we also concluded one other thing. Do you know for sure who killed Irene. We concluded those three things. Now Don, I’ve been involved in this type of work for a long time and there’s always two sides to every story. OK. What I don’t know right now for sure I know you contracted with someone to kill, not necessarily kill your wife, but to harm her. Sometimes when you make up a contract like this things go a little bit wrong and sometimes maybe you had no intentions of say, really killing your wife when you hired this guy but what happened he went a little bit too far and she died. Now I don’t know for sure at this point whether that’s what happened or in fact you actually did ask this person to [285]*285kill her. Don, again, many many things cause this. It can be caused from an unhappy marriage. It can be caused from pressure at home, pressures at work. In other words, what I’m saying is sometimes you get up in the morning and you touch something and everything just sort of turns to shit, doesn’t it. I think we all have these days. Don, I can look at you now and some of the visual signs are beginning to really set in, the dryness of the mouth, the dilation of the eyes, you’ve got a lot on your mind now, the thing is Don that to get some psychological and also physical relief from this I would suggest now that you start telling the truth. Tell me exactly what happened, how this thing got started.’
“ ‘Sure, OK, that’s what I want you to be. Now, Don I also feel that you wanted to dispose of your wife from looking at your charts and I think right now you’re rationalizing a little bit.’
“ ‘Now wait a minute. Don, before you say too much more and get yourself out on a limb, I know you’re not being truthful and I’ll tell you why. Some of the names I read to you we know you talked to, OK?’
“ ‘Sure, we know you talked to them, and we know that the initial contact back in July and August was to kill your wife, OK? One of these individuals has already come forward, and given a complete statement and this is the reason you’re down here. So we can more or less verify to see if he’s telling the truth.’ ” Schlise, supra at 40-41.
At the Schlise trial, Anderson’s testimony relating to the results of the polygraph examination and the defendant’s statement in the post-test interview were received over the defense counsel’s objection on the grounds of lack of voluntariness and the absence of a Stanislawski stipulation. This court set aside the conviction and remanded the case for a new trial as the test results and Schlise’s post-examination statement were admitted into evidence without a written stipulation and because we had serious doubts regarding the voluntariness of the defendant’s confession due to the psychologically coercive tactics of the examiner as detailed in the record. Schlise, [286]*286swpra at 49. We recited our concern respecting the vol-untariness issue in the following language:
“We further conclude that upon the remand for a new trial upon proper motion by the defendant, another Good-child hearing should be conducted to determine whether the post-mechanical phase of the polygraph examination was so psychologically coercive as to render the defendant’s admissions involuntary, and whether the subsequent statements were voluntary or so tainted by the prior statement to Anderson (if it was) so it cannot be said they were freely and voluntarily given.” Id.
Thus, the written stipulation issue was not the sole concern in Schlise regarding the decision to exclude the defendant’s statement in the post-test interview.
There are a number of important differences between the facts of this case and those of Schlise. In Schlise, we concluded that the Stanislawski stipulation rule applied because: “The post-mechanical interview was so closely associated with the mechanical or electronic testing, both as to time and content, that it must be considered as one event and because of the lack of a Stanislawski stipulation excluded from evidence.” (Emphasis supplied.) Schlise, supra at 48-44. The close association in both time and content between the mechanical test and the post-test interview in Schlise arose from the fact that the interview occurred only twenty minutes after the mechanical test (time) and that the examiner used concurrent test results and psychologically coercive tactics that posed serious questions as to the voluntariness of Schlise’s statements (content).
In this case, contrary to Schlise, there was no interpretation and use of concurrent test results as no mechanical test was given to Barrera on the date of the confession, April 4, 1977. Thus, this case lacks the close association between the content of both the mechanical test and the interview in Schlise. Moreover, since a mechanical [287]*287test was not administered in this ease on April 4, 1977, the only test results that this interview could be associated with as to the time element are the inconclusive results obtained on the 7th and 17th of March, some 28 and 18 days before the confession. Thus, as contrasted with the twenty minute time span in Schlise, the requirement of a close association in time is not present in this case. Further, in support of our conclusion that this case lacks a temporal association between the pretest interview and a mechanical test, we quote the following' language from Schlise:
“This is not intended to suggest that all post-examination interviews between a subject and the examiner will be subsumed into the special category of polygraph evidence and fall within Stanislawski. Turner v. State, 76 Wis.2d 1, 250 N.W.2d 706 (1977), and McAdoo v. State, 65 Wis.2d 596, 228 N.W.2d 521 (1974) ... are clear authority for the opposing view, i.e., that in certain factual settings such interviews may be found to be totally discrete from the examination which precedes them. It should be noted, in this regard, that the Anderson interview at issue in Turner took place six days after the polygraph test.” (Emphasis supplied.) Schlise, supra at 42.
It is apparent from this quotation that the Schlise court determined that the passage of six days in the Turner case between the administration of a polygraph examination and an interview with the examiner on the date a second test was scheduled was sufficient to render the interview a “discrete” event. As previously noted, Barrera was tested on March 7 and March 17, 28 and 18 days prior to the April 4 interview. Thus, under our holding in Turner v. State, 76 Wis.2d 1, 250 N.W.2d 706 (1977) as distinguished in Schlise, the long lapse of time in this case between the administration of a mechanical test and the date of the confession, rendered the April 4th interview a discrete event in relation to [288]*288the prior two tests, and, therefore, this interview was not closely associated in time with a mechanical test.
Schlise, supra, Turner, supra and McAdoo v. State, 65 Wis.2d 596, 223 N.W.2d 521 (1974), demonstrate that insofar as the written stipulation rule is concerned, admission of statements made during the course of an interview with a polygraph examiner is dependent upon whether the interview is a discrete event with respect to the mechanical portion of a polygraph test. Under Schlise, the interview will not be considered a separate event where it is “so closely associated with the mechanical or electronic testing, both as to time [20 minutes] and content, that it must be considered as one event. . . .” Id. at 43. This determination can only be made upon a careful consideration of the totality of the facts and circumstances in the individual case. In Schlise, the close association between the mechanical test and the interview that produced the confession was as noted above supplied by the concurrent test results and psychologically persuasive questioning techniques which under a consideration of the circumstances of the post-test interview appeared to present a substantial voluntariness issue. As compared with Schlise, the confession in this case was made in a pretest interview some 18 days after the examiner’s last contact with the defendant. This, in turn, precluded the examiner from confronting the defendant with concurrent test results. But, after a search of the record, we disagree with the defense counsel’s argument that the examiner in this case used questionable psychologically coercive tactics to procure Barrera’s confession.5
Thus, in the absence of use of concurrent test results and psychologically persuasive questioning tactics, this case lacks the close association in content between a [289]*289mechanical test and the pretest interview that was present in Schlise. To repeat, the fact that 18 and 28 days elapsed between the time of the April 4 interview and Barrera’s previous tests clearly demonstrate that this interview was not associated in time with a mechanical test. Turner, supra. Thus, we have distinguished the facts and circumstances in this case from those of Schlise in that the April 4 interview was a discrete and separate event and not “so closely associated with the mechanical or electronic testing, both as to time and content, that it must be considered as one event. . . .” Schlise, supra at 43. Therefore, we hold that the Stanis-lawski written stipulation rule does not, as the defendant contends, bar the receipt of Barrera’s confession in this case.
Voluntariness
At trial the court held a second Goodehild hearing to determine if the defendant’s confession to Anderson during the course of the April 4 interview was voluntary and given after a valid waiver of Miranda rights. The April 4 interview was recorded on tape and the court reviewed this tape prior to the hearing.6 At the hearing, Barrera and Anderson testified to the content of the interview, and the trial judge concluded orally that the confession was voluntarily given after a knowing and intelligent waiver of Miranda rights and therefore admissible. On review, the defendant challenges this ruling claiming that the confession was not voluntary.
Anderson, before commencing the interview, read the Miranda rights to Barrera in the presence of his at[290]*290torneys and obtained the defendant’s signature and the signature of one of his attorneys on a Miranda, waiver form.7 The interview lasted between 40 to 45 minutes. During the course thereof, Anderson confronted Barrera with the results of a polygraph test that had been given to Frederico Garcia, stating that Garcia had told the truth when he said that the defendant shot Mrs. Bussie. Anderson testified that at this point he sensed that Barrera was ready to confess and he decided to pursue this possibility. Thereafter, Anderson accused the defendant of shooting Mrs. Bussie and stated that he wanted to know why. Anderson frequently asked the defendant to tell the truth and engaged in a discussion of religion and religious convictions which ended in a statement that Barrera would have to face up to it when he met his savior. Up to this point, the defendant had been giving non-verbal responses. Anderson asked Barrera if he would talk to him if the tape recorder were turned off. The defendant gave an affirmative verbal response and the recorder was turned off for about five minutes. During this period Barrera cried and confessed. Anderson then turned the recorder back on and capsulized the defendant’s statement on tape. The defendant then requested his attorney who was summoned immediately and the interview was terminated.
At the Goodchild hearing, Barrera indicated that his confession was induced by the talk about God and religion stating “that’s my weak spot . . . because I really love God . . . and by the disclosure of Garcia’s polygraph test results.
The defendant claims that Anderson was “patronizing” Barrera and that his references to God, his inform[291]*291ing the defendant that Garcia had been truthful when he denied shooting Mrs. Bussie, together with his continued requests that the defendant tell the truth, brought overwhelming coercive psychological pressure to bear on Barrera and thus rendered the confession involuntary.
The trial court found that Barrera’s statement to Anderson on April 4, 1977, was voluntary beyond a reasonable doubt. Since the questioning of an accused by a polygraph examiner constitutes custodial interrogation, Wentela v. State, 95 Wis.2d 283, 292, 290 N.W.2d 312 (1980), the rules regarding the voluntariness of statements in this setting apply. Accordingly, this court will affirm a trial court’s determination with respect to voluntariness unless it appears that the findings made were against the great weight and clear preponderance of the evidence. Turner, swpra at 17; Grennier v. State, 70 Wis.2d 204, 209, 234 N.W.2d 316 (1975); McAdoo, supra at 605.
Voluntariness is determined by looking to the “totality of the circumstances” surrounding the making of the statement. State v. Schneidewind, 47 Wis.2d 110, 176 N.W.2d 203 (1970). The pertinent inquiry is whether the confession was coerced or the product of improper pressures exercised by the person or persons conducting the interrogation. Turner, supra at 18. This assessment calls for a balancing of the personal characteristics of the confessor with the pressures brought to bear upon him. Turner, supra at 18; Grennier, supra at 210, citing State v. Wallace, 59 Wis.2d 66, 81, 207 N.W.2d 855 (1973).
The personal characteristics of the accused that should be considered in this balance are “. . . his age, his education and intelligence, his physical and emotional con[292]*292dition, and his prior experience with the police.” Gren-nier, supra at 212; See also: Schneidewind, supra at 117 and McAdoo, supra at 606. These characteristics are to he weighed against “any inducements, methods and stratagems which were used to persuade the accused to confess.” Schneidewind, supra at 117, citing Lynumn v. Illinois, 372 U.S. 528 (1963). This includes a consideration of the length and conditions of the questioning and the psychological and physical pressures exercised by the interrogator. Grennier, supra at 212. It is also relevant whether the confessor was apprised of his Miranda rights, specifically his right to counsel and his privilege against self-incrimination. Id. at 210-211.
The record shows that the defendant was 26 years of age, from a Latino background and spoke and understood English very well and further that he was treated well by Wisconsin authorities and in good physical condition. The record does not disclose the extent of his education or whether he had prior involvement with law enforcement officers. However, it is eminently clear that Barrera understood his constitutional rights as he had been advised of them on at least four prior occasions and had in fact exercised them to terminate the April 4 interview.
In his testimony at the second Goodchild hearing, Barrera stated that it was the talk about God and Garcia’s polygraph results that induced him to confess. The confrontation of the defendant with information against him “whatever that may be, does not amount to the utilization of overwhelming force or psychology. Krue-ger v. State, 53 Wis.2d 345, 356, 192 N.W.2d 880, 886 (1972).” Turner, supra at 22. Turning to the reference to God, the defendant does not refer us to a case8 and [293]*293we have been unable to find any that are supportive of the claim that a discussion of religion and religious convictions concluding with the statement to Barrera that he would have to face up to it when he met his maker was so overbearing as to render his confession involuntary. Furthermore, under the totality of the circumstances test, we agree with the trial court’s finding that the confession was freely and voluntarily given after a thorough rendition and understanding of the Miranda rights and therefore admissible.
Lie Test Reference
The defendant’s final contention is that the trial court erred in failing to order a mistrial or give a cautionary instruction after the state’s principal witness, Garcia, made reference to a lie test at the close of his direct examination. The exact testimony is as follows:
“Q. Freddie, your attorney told you that we had an agreement regarding your testifying here today: didn’t he?
“A. Yes, he did.
“Q. Based upon that agreement, what were you to do ?
“A. Tell the truth.
“Q. Were you to testify in this trial, also?
“A. Yes.
“Q. The reason for your testimony and telling the truth, did your attorney tell you whether or not you would be prosecuted for murder?
“A. Right, he told me I wouldn’t be prosecuted for murder.
“Q. Did he tell you that you would be prosecuted for robbery?
“A. Yes, he told me I would be prosecuted for robbery; that based upon my testimony and another lie test, telling the truth.”
[294]*294Counsel for the defendant, in the absence of the jury, then moved for a mistrial. The court, being informed that Garcia had been warned against referring to his polygraph examination in front of the jury, advised the prosecutor to caution Garcia again and denied the motion for mistrial stating that it did not believe that Garcia’s reference to a “lie test” was “so prejudicial as to cause that result.” Defense counsel did not request a cautionary instruction and none was given.
This court has consistently held that the failure of a trial court to sua sponte instruct the jury to disregard certain testimony will not support a claim for prejudicial error. Wkitty v. State, supra at 290 and cases cited therein. This rule is based on the policy of placing the primary duty of trying a lawsuit upon trial counsel, not the trial judge. Id. We see no reason for changing this rule in the case herein. Thus, we find no error in the trial court’s failure to instruct the jury to disregard Garcia’s reference to a lie test in the absence of a request by defense counsel.
The central issue presented here is whether the trial court committed reversible error in denying the defendant’s motion for a mistrial, or, conversely, assuming that Garcia’s reference to his lie test was error, whether this statement was harmless error.
The defendant argues that reversal is required because the jury could infer from the reference to his lie test that Garcia, the state’s major witness, was telling the truth.
The test for determining harmless error was most recently set out in Pohl v. State, 96 Wis.2d 290, 311, 312, 291 N.W.2d 554 (1980) :
“ * “Errors committed at trial should not overturn the conviction unless it appears the result might probably have been more favorable to the party complaining had the error not occurred.” Hart v. State, 75 Wis.2d 371, [295]*295249 N.W.2d 810 (1977). In Wold v. State, 57 Wis.2d 344, 356, 204 N.W.2d 482 (1973), a case involving improperly admitted evidence, the court stated:
“ ‘ “The test of harmless error is not whether some harm has resulted, but, rather, whether the appellate court in its independent determination can conclude there is sufficient evidence, other than and uninfluenced by the inadmissible evidence, which would convict the defendant beyond a reasonable doubt. See Harrington v. California (1969), 395 U.S. 250, 89 Sup. Ct. 1726, 23 L. Ed.2d 284. This test is based on reasonable probabilities.”
“ ‘Other formulations of the harmless error test would require reviewing courts to set aside the verdict and judgment unless sure that error did not influence the jury or had but only slight effect. Kelly v. State, 75 Wis.2d 303, 317 n. 3, 249 N.W.2d 800 (1977) and concurring opinion at 321.’ Id. at 308.”
The questioned testimony was a brief, vague reference to a polygraph examination that had been taken by the witness and was not at all related to the question of Barrera’s guilt. Moreover, in view of the overwhelming evidence of Barrera’s guilt and the fact that Garcia’s testimony relating the circumstances of the two killings, Mrs. Bussie in Beaver Dam and Kathy Evans in Missouri, was wholly corroborated by the polygraph examiner, Robert Anderson, who related the confession that was given him by the defendant, we conclude that disregarding the assumed inadmissible evidence, there was sufficient evidence to convict the defendant beyond a reasonable doubt. Further, there is no evidence that Garcia’s reference to his polygraph examination influenced the jury. Thus, we conclude that in the absence of the defense attorney’s request for a precautionary instruction, the judge’s failure to give the same was not error. On the other hand, were we to classify the failure to give an instruction concerning the “lie test,” the error [296]*296would be classified as harmless, and therefore, not a ground for reversal.
By the Court. — The decision of the court of appeals is reversed and the judgment of conviction is affirmed.