HIGGINS, Judge.
Michael A. White was convicted by a jury of capital murder, § 565.001, RSMo 1978; his punishment was fixed at imprisonment for life without eligibility for parole or probation for fifty years, § 565.008, RSMo 1978. Judgment was rendered accordingly. He charges error to the aider liability instructions; the refusal to grant his motion to suppress an incriminating statement; and the application of the statute on peremptory juror challenges. Affirmed.
I.
The evidence supports defendant’s conviction for the murder of Susie Hawkins. It established that on February 5, 1979, between 8:30 and 9:00 p. m., Hardy Bivens arrived at Michael White’s house. As previously arranged, Bivens was to give White a ride to the home of his brother, Charles White. Before leaving Michael’s home, Bivens telephoned Janice Thompson. Bivens and Ms. Thompson had had a disagreement the previous day during which he threatened her. During the telephone conversation Ms. Thompson told Bivens that she was going to the supermarket, and would call Bivens when she returned home. Shortly after this conversation, Ms. Thompson and her step-sister Susie Hawkins, both fifteen-year-old girls, walked to the store. At approximately the same time Bivens and defendant also departed supposedly for the home of defendant’s brother. Instead, Bivens drove directly to the store where Ms. Thompson said she was going. Sometime prior to arriving at the store defendant placed a loaded pistol on the front seat of the car between himself and Bivens; he carried extra bullets in his pocket. Bivens met the girls in the store and offered them a ride home; they accepted.
As Bivens drove from the store, he began to question Ms. Thompson regarding their argument of the previous day. An argument ensued between Bivens and Ms. Thompson. A short time later Bivens stopped the ear; defendant and Bivens got out, spoke briefly, then re-entered, with defendant driving. The argument continued until Bivens picked up the gun and shot both girls, wounding Ms. Hawkins in the mouth and Ms. Thompson in the jaw. Following Bivens instructions, defendant drove to 23rd and Cass in the City of St. Louis, where an apartment building stood vacant.
Upon arriving, Bivens got out and ordered the girls out of the car. Bivens instructed defendant to drive around the block. While defendant was circling the block, Bivens forced the girls into the building, then ordered them to sit on the floor. The girls pleaded with Bivens, promising to remain silent about the incident. Bivens [942] denied their pleas, but fired no shots until he heard the defendant sound the horn after completing his trip around the block. After emptying his gun, Bivens ran back to the car where he demanded and received more bullets from defendant. Bivens ran back to the building as defendant drove around the block again. When Bivens entered the building he found only Ms. Hawkins; Ms. Thompson had fled. As she escaped, she heard more shots coming from the building. Bivens returned to the car and told defendant that Ms. Thompson had fled. Defendant disposed of Ms. Hawkins groceries, and he and Bivens returned to look for Ms. Thompson. While searching, defendant saw Ms. Hawkins on the floor coughing. Upon hearing a siren, Bivens and defendant fled together. Ms. Hawkins died as a result of her wounds. Both defendant and Bivens were arrested late the same evening.
II.
The jury was instructed on all degrees of homicide as required by MAI-CR2d 15.00 series. The capital murder issue was submitted to the jury by two general instructions on criminal responsibility, a verdict directing instruction and a converse instruction. Instruction No. 5 was in form MAI-CR2d 2.101 (derived from § 562.036, RSMo 1978):
1. A person is guilty of an offense if it was committed by conduct for which he is criminally responsible, whether that conduct was his own or that of another person or both his own conduct and that of another.
2. A person is criminally responsible for the conduct of another in committing a particular offense when, either before or during the commission of an offense, with the purpose of promoting the commission of that offense he aids or agrees to aid or attempts to aid such other person in committing that offense.
3.The presence of a person at or near the scene of an offense at the time it was committed is alone not sufficient to make him responsible therefor, although his presence may be considered together with all of the evidence in determining his guilt or innocence.
Instruction No. 6 was in form MAI-CR2d 2.14 (derived from § 565.051, RSMo 1978):
In this case you will be instructed that you may find the defendant either not guilty of any offense or guilty of either capital murder or second degree murder or manslaughter. In that connection you are instructed that when two persons are criminally responsible for an offense which is divided into greater and lesser offenses, each such person is guilty of that offense, greater or lesser, which is compatible with that state of mind with which he acted in committing the offense and compatible with his own accountability for any aggravating or mitigating fact or circumstance.
Instruction No. 7 was in form MAI-CR2d 2.12 (derived from § 562.041, RSMo 1978) combined with MAI-CR2d 15.02:
If you find and believe from the evidence beyond a reasonable doubt.
First, that on the 5th day of February, 1979, Hardy Bivens with the aid or attempted aid of the defendant committed the crime of capital murder of Susie Hawkins, in that Hardy Bivens, with the aid or attempted aid of the defendant caused the death of Susie Hawkins by shooting her, and in that Hardy Bivens, with the aid or attempted aid of the defendant knew he was' practically certain to cause the death of Susie Hawkins, and in that Hardy Bivens with the aid or attempted aid of the defendant considered taking the life of Susie Hawkins and reflected upon this matter coolly and fully before doing so, and
Second, that the defendant either before or during the commission of the [943] offense of capital murder with the purpose of promoting its commission aided Hardy Bivens in committing that offense,
then you will find the defendant guilty of capital murder.
However, if you do not find and believe from the evidence beyond a reasonable doubt each and all of the foregoing propositions, you must find the defendant not guilty of that offense.
Instruction No. 8 was in form MAI-CR2d 3.02:
If you do not find and believe from the evidence beyond a reasonable doubt that Hardy Bivens with the aid or attempted aid of the defendant did consider taking the life of Susie Hawkins and did reflect upon this matter coolly and fully before doing so, you must find the defendant not guilty of capital murder.
Instruction B, refused by the court, was offered by defendant for use in place of or in addition to instruction No. 8:
If you do not find and believe from the evidence beyond a reasonable doubt that the Defendant did consider taking the life of Susie Hawkins and did reflect upon this matter coolly and fully before doing so, you must find the Defendant not guilty of Capital Murder.
A.
Appellant contends Instruction No. 7 was improperly constructed. He argues first that the “practically certain” clause in No. 7 was erroneously included because it applies only to cases where the defendant is charged with an offense committed by another person but other than the original offense contemplated by the defendant. (Ex. felony murder) MAI-CR2d 2.12, Note on Use 6.
This argument overlooks the inclusion of this clause in MAI-CR2d 15.02 on capital murder which in the present case was combined with MAI-CR2d 2.12. This clause was properly included in Instruction No. 7 because it is a component of the capital murder instruction.
B.
A second argument of improper construction concerns the use of “will” instead of “may” in the last line of the first paragraph. Note on Use 3 of MAI-CR2d 2.12 provides, “The word ‘may’ must be used ... in any case where Section 562.051 is applicable.” This Note on Use refers to MAI-CR2d 2.14 Note on Use 3 which indicates that MAI-CR2d 2.14 and by reference thereto the word “may” in MAI-CR2d 2.12 must be used “when two or more persons are criminally responsible for an offense divided into degrees,” citing § 562.051, RSMo 1978.
Prejudicial effect of giving or failure to give an instruction in violation of MAI-CR2d and the applicable Notes on Use is for judicial determination. Rule 28.02(e); State v. Williams, 611 S.W.2d 26, 29 (Mo. banc 1981); State v. Heitman, 589 S.W.2d 249, 255 (Mo. banc 1979); State v. Graves, 588 S.W.2d 495, 497 (Mo. banc 1979). Such errors are presumptively prejudicial unless the contrary is clearly demonstrated. State v. Williams, supra; State v. Graves, supra; State v. Clifton, 549 S.W.2d 891, 893 (Mo. App. 1977). This Court must review all submitted instructions together to determine if the use of “will” in Instruction No. 7, resulted in prejudicial error. State v. Vainikos, 366 S.W.2d 423, 425 (Mo. banc 1963); State v. Harris, 602 S.W.2d 840, 847 (Mo.App.1980).
The use of “may” “when two or more persons are criminally responsible for an offense divided into degrees”, (§ 562.051, RSMo 1978) serves to inform the jury that they are not required to find each defendant guilty in the same degree. Therefore, if the jury understood it could consider defendant’s liability as to each degree, then the use of “will” instead of “may” has no prejudicial effect. In this case, the jury was instructed on all applicable degrees of [944] homicide and it did consider each degree of homicide. Instruction No. 6 was also submitted and informed the jury that the defendant is guilty to the degree compatible with his culpability. During its deliberation the jury panel sent a series of questions to the trial judge one of which asked: “What is the earliest time for parole for all three sentences, what is the minimum and maximum time for all three sentences?” Considered together and in these circumstances, the instructions conveyed to the jury its duty to consider the various degrees of culpability, and the use of “will” in Instruction No. 7 did not mislead the jury.
C.
Appellant contends that Instructions No. 6 and 7 improperly stated the law by failing to require the jury to find that defendant had the intent of the underlying felony. Appellant’s argument is based on § 562.-0362 and § 562.0513, RSMo 1978. He construes these two sections as requiring the aider to have the intent of the underlying offense in addition to the intent to purposely promote the commission of the offense, as required by § 562.041.1(2), RSMo 1978 4. Thus, appellant argues that under § 562.036 and § 562.051, RSMo 1978, the jury must find: (1) that the aider purposely promoted the commission of the murder, and (2) aided in the murder only after coolly and fully deliberating on the matter (the requisite intent for capital murder). In appellant’s view an aider must have two intents, and the jury must be so instructed.
The instructions challenged by the appellant employ the language of the applicable statutes. Accordingly, appellant’s attack cannot be sustained on the grounds the instructions do not correctly state the law; to the contrary the instructions mimic the statutes. Thus, appellant’s argument is directed at how the statute is construed, rather than the construction of the instructions.
The goal of statutory interpretation is to determine and give effect to the intent of the legislature. State v. Kraus, 530 S.W.2d 684, 685 (Mo. banc 1975). To this purpose, the court considers a particular statute together with related statutes which may shed light on its meaning, 530 S.W.2d at 686-87. The court must also consider the purpose or goal of the statute and any relevant conditions existing at the time it was enacted. State v. Wright, 515 S.W.2d 421, 427 (Mo. banc 1974).
Appellant’s reading of this statutory scheme is too broad in the sense that he views it as requiring the jury to find two specific intents. If the Legislature had intended to require an aider to have a dual intent, it would have said so in the statutes. To the contrary, the only requirement expressed in the three sections is found in § 562.041.1(2), RSMo 1978. The comment which accompanies § 562.041, V.A.M.S., 1979 states that “the section requires a ‘purpose to promote the commission of an offense.’ ” There is no mention of an additional or separate mental state in this comment or the comments to the other two sections.
[945] Section 562.016(2), RSMo 1978 states “A person ‘acts purposely’, or with purpose, with respect to his conduct or to a result thereof when it is his conscious object to engage in that conduct or to cause that result.” Therefore to be found guilty of a particular offense, an aider must aid another or others with the conscious object of causing that offense. A finding that the aider had this intent is equivalent to finding that the aider and active participant shared a common intent or purpose.
The pre-code corollary to § 562.041, RSMo 1978 was § 556.170, RSMo (Repealed) which abrogated the distinction between principals and accessories. State v. West, 484 S.W.2d 191, 195 (Mo. 1972); State v. Spica, 389 S.W.2d 35, 40 (Mo. 1965), cert. denied, 383 U.S. 972, 86 S.Ct. 1277, 16 L.Ed.2d 312 (1966). State v. Butler, 310 S.W.2d 952, 957 (Mo. 1958). It made no reference to the elements of aider liability. However, in State v. Grebe, 461 S.W.2d 265 (Mo. banc 1970), this Court held that the intent to aid or purposeful aiding is an essential element of aider liability. It is established in the pre-code common law of this state that those “who act together with a common intent and purpose in the commission of a crime are equally guilty, if they share consciously in the criminal act as something they intend to bring about.” State v. Goodman, 482 S.W.2d 490, 492 (Mo.1972); State v. Garton, 371 S.W.2d 283, 289 (Mo. 1963); State v. Johnson, 347 S.W.2d 220, 222 (Mo. 1961); State v. Thomas, 595 S.W.2d 325, 328 (Mo.App. 1980); State v. Collins, 520 S.W.2d 155,157 (Mo.App. 1975). Cf. State v. Lute, 608 S.W.2d 381 (Mo. banc 1980). Where, as in the present consideration, the wording of a new statute follows the language of the pre-existing common law it must be presumed the legislature intended the same meaning. It is irrational to say that the same language has two separate meanings when used in the first instance by the courts and employed subsequently by the legislature. Section 562.041, RSMo 1978 codifies that which was previously established under common law. Cf. State v. Mitchell, 611 S.W.2d 223, 227 (Mo. banc 1981); State v. Pierson, 610 S.W.2d 86, 91 (Mo.App. 1980).
Appellant’s argument emphasizes the words “with the required culpable mental state” found in § 562.036, RSMo 1978 and the provision in § 562.051, RSMo 1978 that “each person is guilty of such degree as is compatible with his own culpable mental state ...” Section 562.036, RSMo 1978 provides that one may be liable for the conduct of another with the proviso that the defendant have his own culpable mental state. Comment to § 562.036, Y.A.M.S. 1979. As shown above, the required mental state is the purpose to promote the commission of the offense. Section 562.051, RSMo 1978 expressly permits variance in the degree of culpability of one defendant relative to another. This express provision is necessary because “At common law there was a question whether an ‘aider and abettor’ could be guilty of a higher (or lower) degree of the offense assisted.” Comment to § 562.051, Y.A.M.S. 1979. When, as in the present case, the aider is found to have purposely aided in capital murder and thus has the same intent of the active participant, all other things being equal, they are liable to the same degree. Situations can exist where the liability of each is not the same. In such cases, § 562.051, RSMo 1978, permits the defendant or the state to present evidence aggravating or mitigating the matter. For example, defendant may introduce evidence showing that he did not have the purpose or conscious object of aiding in capital murder. Contrary to appellant’s argument, § 562.051, RSMo 1978, does not create any elements of intent in addition to that of § 562.041, RSMo 1978. MAI-CR2d 2.14 informs the jury that it is to consider the defendant’s guilt or innocence as to each degree of the offense independently from other defendants who might be liable for the same offense.
In this case, the jury was instructed and found defendant “with the purpose of [946] promoting its commission aided Hardy Bivens in committing that offense” [capital murder], which is to say, acting with the conscious object of causing premeditated murder, defendant aided in causing capital murder. Thus the jury necessarily found that defendant had the same intent as the active participant, Hardy Bivens. The jury was free to find the defendant did not purposely aid in premeditated murder because it was instructed as to lesser degrees of homicide and further so instructed by Instruction No. 6.
Instruction No. 8 was a proper converse in that it controverted one of the elements of the state’s case and followed the form required by MAI-CR2d 3.02. As stated in the Notes on Use to MAI-CR2d 3.02 a converse need not cover all elements included in the verdict directing instruction.
The court’s instructions were properly composed under the directives of MAI-CR2d and correctly stated the law of aider liability as contained in the applicable statutes.
D.
Defendant’s tendered Instruction B was properly refused because it is confusing and inaccurate. Instruction B is not couched in the language of aider liability in § 562.041, RSMo 1978 because it suggests that defendant committed the act of capital murder himself. Although one who aids in capital murder is responsible as if he had performed the act himself, it is a misstatement of fact to say this defendant so acted. In the sense that this instruction would require the jury to find the defendant committed the act of capital murder himself, it misstates the law of this ease. A converse must correctly declare the law before refusal to submit becomes error. State v. McWilliams, 331 S.W.2d 610, 613 (Mo. 1960).
III.
Appellant challenges the admission of a tape recorded statement which he asserts was made in return for a promise that the would be released, and thus was involuntarily made. Appellant points to an incident5 which he asserts constitutes an implied promise of leniency.6
The state bears the burden of proving, by a preponderance of the evidence, the voluntariness of a confession. Lego v. Twomey, 404 U.S. 477, 92 S.Ct. 619, 30, L.Ed.2d 618 (1972); Miranda v. Arizona, 384 U.S. 436, 86 S.Ct. 1602, 16 L.Ed.2d 694 (1966); State v. Hughes, 596 S.W.2d 723, 726 (Mo. banc 1980); State v. Olds, 569 S.W.2d 745, 751 (Mo. banc 1978). The state must show that “defendant was effectively [947] advised of his rights and then intelligently and understandingly declined to exercise them.” State v. Alewine, 474 S.W.2d 848, 851 (Mo. 1971).
At the suppression hearing the state offered into evidence the tape recorded statement and the testimony of Sergeant McDonagh, one of the officers present when the statement was made. The tape recording begins with the giving of the warnings of rights as required by Miranda v. Arizona, supra. Defendant after expressing full understanding declined to exercise these rights.7 The statement was an attempt by defendant to clear himself of culpability rather than to confess guilt. He was promised that he would be released pending a decision by the Grand Jury; he was released. There is no evidence that the release was contingent upon the making of a statement or which otherwise controverts the state’s evidence showing the statement was voluntarily made. On cross-examination, Sergeant McDonagh indicated that some conversation had taken place prior to when the recording began, yet the evidence offered by the state is not controverted by whatever inference can be drawn therefrom. The question is “whether the evidence was sufficient to sustain the trial court’s finding that the statement was voluntarily given,” State v. Alewine, 474 S.W.2d at 852; sufficient evidence was presented to support the trial court’s ruling.
IV.
Appellant asserts that he was entitled to twelve peremptory challenges pursuant to § 546.180, RSMo (Repealed), which was in effect when the offense occurred. The trial court proceeded under the newly enacted § 546.180, RSMo Supp. 1980, effective at the time of trial which afforded defendant a lesser number of peremptory strikes. Appellant argues that the use of the new provision in lieu of the former violated his right to a fair and impartial jury and to due process.
A.
Missouri Constitution, art. I, § 22(a) provides “That the right of trial by jury as heretofore enjoyed shall remain inviolate; . ... ” Appellant suggests this provision is a sort of specialized prohibition against retroactive application of changes in jury selection procedure. He cites no authority in support of this interpretation and our research reveals none.
Although the Missouri Constitution generally prohibits ex post facto laws and retroactive application of enacted laws, Mo. Const., art. I, § 13, V.A.M.S., there is an exception for statutory changes which have no effect on any substantive right of the parties. A statute dealing only with procedure applies to all actions falling within its terms whether commenced before or after the enactment. State ex rel. St. Louis-San Francisco Ry. Co. v. Buder, 515 S.W.2d 409, 410 (Mo. banc 1974); Darrah v. Foster, 335 S.W.2d 24, 29 (Mo. 1962); Clark v. Kansas City, St. Louis & Chicago Railroad Co., 219 Mo. 524, 527, 118 S.W. 40, 44 (1962). In State v. Eaton, 316 Mo. 995, 292 S.W. 70 (1927), the law concerning the number of challenges afforded a defendant was enacted after the offense occurred and was applied to the defendant’s trial. This Court held: “The number of challenges to which a defendant on trial is entitled is purely a procedural matter and does not constitute a substantial right” Id., 292 S.W. at 74.
B.
Defendant’s right to a jury trial as guaranteed by U.S. Const, amend. VI made applicable to the states by U.S. Const, amend. XIV was not violated by the application of § 546.180, RSMo Supp. 1980. Ap[948] pellant concedes that the United States Supreme Court has held that certain procedural issues do not fall within constitutional requirements. Apodaca v. Oregon, 406 U.S. 404, 92 S.Ct. 1628, 32 L.Ed.2d 184 (1972) (unanimous jury verdict not required by the Sixth Amendment) and Williams v. Florida, 399 U.S. 78, 90 S.Ct. 1893, 26 L.Ed.2d 446 (1970) (twelve person jury in robbery case not a necessary requirement in trial by jury). He asserts, however, that the number of peremptory challenges more accurately falls within the class of cases related to the composition of the jury, citing Taylor v. Louisiana, 419 U.S. 522, 95 S.Ct. 692, 42 L.Ed.2d 690 (1974) (Sixth Amendment prohibits barring women from jury); Alexander v. Louisiana, 405 U.S. 625, 92 S.Ct. 1221, 31 L.Ed.2d 536 (1972) (racial discrimination in grand jury selection unconstitutional), Carter v. Jury Commissioner, 396 U.S. 320, 90 S.Ct. 518, 24 L.Ed.2d 549 (1970) (discriminatory exclusion of a class from jury rolls unconstitutional).
The cases upon which appellant relies require a jury roll to include members of the entire spectrum of the community under the Sixth Amendment. As said in Williams v. Florida, supra,
the essential feature of a jury obviously lies in the interposition between the accused and his accuser of the common sense judgment of a group of laymen and in community participation and shared responsibility that results from that group’s determination of guilt or innocence. The performance of this role is not a function of the particular number of the body that makes up the jury.
Id. 399 U.S. at 100, 90 S.Ct. at 1905.
Although the use of peremptory challenges clearly affects the composition of the jury, it does so in a way which is distinct from assuring that the entire community is represented on the panel. These two selection processes are actually opposite to each other. The cases cited by appellant prohibit race or sex discrimination in the compilation of jury rolls. Peremptory jury strikes, however, may be exercised on grounds “normally thought irrelevant to legal proceedings or official action, namely, the race, religion, nationality, occupation or affiliation of people summoned for jury duty.” Swain v. Alabama, 380 U.S. 202, 220, 85 S.Ct. 824, 835, 13 L.Ed.2d 759 (1965). The selection of potential jurors in the first instances is a separate matter from their subsequent elimination at trial by peremptory challenge. The Sixth Amendment protection covering the former does not encompass the latter.
The judgment is affirmed.
DONNELLY, C. J., RENDLEN, WEL-LIVER and MORGAN, JJ., concur.
SEILER, J., dissents in separate dissenting opinion filed.
BARDGETT, J., dissents and concurs in separate dissenting opinion of SEILER, J.