Hastings, C.J.
Defendant, Tony L. Haynie, appeals from the bench trial convictions of six counts of robbery and one count of attempted robbery and his sentences to consecutive terms of imprisonment totaling not less than 68 nor more than 185 years. He assigns as error the admission of his confession into evidence and the excessiveness of the sentences.
Thirteen robberies had occurred in Omaha in which the suspect had been identified as a tall and slender black male around 20 years of age with short hair. The suspect was reported to have a red eye and used a cloth covering over his arm to conceal an alleged weapon. An anonymous tip was provided naming the defendant as the alleged robber. The anonymous caller described the defendant as a thin 28-year-old black male, 6 feet 1 inch tall, with short hair. According to the caller the suspect was unemployed, but had large sums of money and had told friends that he was going to rob 7 Eleven stores to pay for drugs. Robberies had in fact occurred at a 7 Eleven store, a Goodrich Dairy store, and doughnut, pharmacy, and grocery stores, and a robbery had been attempted at a Kwik Shop. The caller said that the suspect had a red eye as a result of a fight with “Crips,” was known as Tony and Slim, and could be found occasionally at 4226 Wirt Street.
Police officers who had investigated the robberies reported that the suspect was unemployed, but had money and used crack cocaine. Following receipt of the anonymous tip a general police broadcast was issued for Haynie’s arrest. The defendant was not found at the Wirt Street address, but neighbors described a car in which they had seen Haynie. After a police officer located the car, the defendant was found at a residential address and arrested. The defendant was advised of his constitutional rights and indicated that he was willing to make a statement. The defendant then confessed to committing 13 robberies. The interrogating officer denied that he made any promises or threats in exchange for the defendant’s statement, but said that he told the defendant during the questioning that he would make a report and indicate that the defendant talked freely, without any hesitation, and that would probably be taken into consideration on how many cases were filed against [482]*482him. The defendant in fact was 6 feet 3 inches tall, weighed 172 pounds, was 29 years of age, and had a red eye when he was arrested.
Defendant made a pretrial motion to suppress all statements made by him to police officers because they were not freely and voluntarily made, were coerced by threats and promises, and were the fruit of an unlawful arrest. The motion was overruled, the defendant waived his right to a jury trial, and the parties stipulated that the police reports would be the only evidence adduced at trial. However, defendant renewed his objection to the admission of his statement. Other than the claimed excessiveness of the sentences, this is the only issue in dispute. The presentence investigation report revealed that the defendant had been fined $25 in 1985 for a welfare fraud conviction. The trial court noted that in most of the robberies the defendant told the victims that he had a gun. Following trial and conviction the defendant was sentenced as previously noted.
We first deal with defendant’s claim that his arrest was not lawful and therefore any confession was the “fruit of the poisonous tree.”
When a law enforcement officer has knowledge, based on information reasonably trustworthy under the circumstances, which justifies a prudent belief that a suspect is committing or has committed a crime, the officer has probable cause to arrest without a warrant. The key to a lawful arrest without a warrant is reasonable or probable cause to believe that a person has committed a crime. State v. Badami, 235 Neb. 118, 453 N.W.2d 746 (1990).
According to Neb. Rev. Stat. § 29-404.02 (Reissue 1989), a peace officer may arrest a person without a warrant if the officer has reasonable cause to believe that such person has committed a felony. Reasonable cause is explained in Neb. Rev. Stat. § 29-404.03 (Reissue 1989) as follows:
In determining whether reasonable cause exists to justify an arrest, a law enforcement officer may take into account all facts and circumstances, including those based upon any expert knowledge or experience which the officer in fact possessed, which a prudent officer would [483]*483judge relevant to the likelihood that a crime has been committed and that the person to be arrested has committed it, and for such purpose the officer may rely on information he receives from any informant whom it is reasonable under the circumstances to credit, whether or not at the time of making the arrest the officer knows the informant’s identity.
According to § 29-404.03 an anonymous tip may be considered along with other facts and circumstances. The U.S. Supreme Court has held that an anonymous letter can provide the probable cause requisite for a search warrant. See Illinois v. Gates, 462 U.S. 213, 103 S. Ct. 2317, 76 L. Ed. 2d 527 (1983). The fourth amendment to the U.S. Constitution makes no distinction in the standards applicable to a determination of probable cause for arrest and probable cause for search and seizure. State v. Dussault, 193 Neb. 122, 225 N.W.2d 558 (1975). Gates is therefore relevant to the case at bar, even though it concerned probable cause requisite for a search warrant rather than for an arrest.
The Court in Gates rejected the rigid test of veracity or reliability and basis of knowledge and adopted the totality-of-the-circumstances test for determining whether an informant’s tip establishes probable cause for issuance of a warrant. The Court noted that an informant’s veracity, reliability, and basis of knowledge are all highly relevant in determining the value of the report, but that they should not be viewed as entirely separate and independent requirements to be rigidly exacted in every case. A deficiency in one may be compensated for by a strong showing as to the other. The Court explained that probable cause is a fluid concept dependent on the assessment of probabilities in particular factual contexts which cannot be reduced to a neat set of legal rules. The Supreme Court recognized the following regarding anonymous citizen informants:
[Anonymous] tips, particularly when supplemented by independent police investigation, frequently contribute to the solution of otherwise “perfect crimes.” While a conscientious assessment of the basis for crediting such tips is required by the Fourth Amendment, a standard that [484]*484leaves virtually no place for anonymous citizen informants is not.
Illinois v. Gates, supra at 462 U.S. at 237-38.
The Nebraska Supreme Court has further explained the following concerning probable cause for a warrantless arrest based on information from an informant:
“ ‘When considering the sufficiency of probable cause based on information supplied by an informant, it is important to distinguish the police tipster, who acts for money, leniency, or some other selfish purpose, from the citizen informer, whose only motive is to help law officers in the suppression of crime.
“ ‘In the latter the rule of prior reliability is considerably relaxed for several reasons. In the first place the citizen informer has rarely had any earlier experience in reporting suspected criminal activity. Furthermore, unlike the professional informant, he is without motive to exaggerate, falsify or distort the facts to serve his own ends.
“ ‘Reliability still must be shown, but it may appear by the very nature of the circumstances under which the incriminating information became known. Any other rule would lead to the totally unacceptable result that public-spirited citizens interested only in law enforcement could seldom furnish information sufficient to establish probable cause.’...”
State v. Blakely, 227 Neb. 816, 822-23, 420 N.W.2d 300, 304-05 (1988).
The defendant contends that there was a wide variation in the descriptions of the robbery suspect provided to the police officers. The descriptions of the suspect as a man between 20 and 30 years old and varying from 5. feet 5 inches to 6 feet 2 inches tall and from 120 to 155 pounds were not that much of a variation from the actual physical characteristics of the defendant previously mentioned. With the addition of the “red eye” description and the independent investigation by the police officers, there certainly was probable cause to believe that the defendant was the man who had been committing these [485]*485robberies.
The more perplexing question deals with the issue of voluntariness. Haynie points out that the State must show that the statement, admission, or confession of the accused was given freely and voluntarily and was not the product of any promise or inducement, direct or implied, no matter how slight, before it will be admitted into evidence. State v. Hall, 237 Neb. 169, 465 N.W.2d 150 (1991).
The basis of the “no matter how slight” rule in Nebraska apparently was first identified in State v. Mayhew, 216 Neb. 761, 765, 346 N.W.2d 236, 239 (1984), wherein this court said:
The holding that any inducement made by a person in authority to a person charged with a crime to obtain a statement or confession will render that statement or confession not voluntary and therefore inadmissible has been long established in our law. In Bram v. United States, 168 U.S. 532, 542-43, 18 S. Ct. 183, 42 L. Ed. 568 (1897), the Supreme Court of the United States quoted with approval from a textbook stating: “ ‘But a confession, in order to be admissible, must be free and voluntary: that is, must not be extracted by any sort of threats or violence, nor obtained by any direct or implied promises, however slight____’ ”
This court has restated this rule many times in opinions following Mayhew, to the point where it almost appears to be a per se rule. However, that is not the case.
Tippitt v. Lockhart, 859 F.2d 595 (8th Cir. 1988), cert. denied 490 U.S. 1100, 109 S. Ct. 2452, 104 L. Ed. 2d 1007 (1989), involved an in-custody statement by a suspect in an aggravated robbery and attempted capital murder case wherein the defendant gave a written statement in which he admitted he was the driver of the getaway car. Two of defendant’s accomplices were charged with aggravated robbery and attempted capital murder. The officers who had arrested defendant promised not to charge him with attempted capital murder in return for his statement. He was given the Miranda warnings, following which he gave a statement which was used against him at his trial on charges of aggravated robbery and theft. As promised, he was not charged with attempted capital murder.
[486]*486In finding that subsequent cases have not applied the Bram standard literally, the Tippitt court cited the following from United States v. Grant, 622 F.2d 308, 316 (8th Cir. 1980):
While the Bram test has long been followed, it has not been interpreted to be applied on a strict, per se basis. [Citations omitted.] Rather, as expressed by the Supreme Court, determinations of voluntariness are based upon an assessment of all of the circumstances and factors surrounding the occurrence when the statement is made. [Citations omitted.] This flexible standard allows for judicial determinations of voluntariness in myriad situations without such decision making being hampered by rigid and potentially artificial restraints. The “totality of the circumstances” inquiry requires the reviewing court to investigate and analyze “both the characteristics of the accused and the details of the interrogation.” [Citation omitted.]
The Tippitt court also cited the following from United States v. Ferrara, 377 F.2d 16, 17 (2d Cir. 1967), cert. denied 389 U.S. 908, 88 S. Ct. 225, 19 L. Ed. 2d 225:
That language [from Bram} has never been applied with the wooden literalness urged upon us by appellant. The Supreme Court has consistently made clear that the test of voluntariness is whether an examination of all the circumstances discloses that the conduct of “law enforcement officials was such as to overbear [the defendant’s] will to resist and bring about confessions not freely self-determined * * [Citations omitted.]
The Tippitt court concluded that the Bram language had not been and should not be interpreted to require the exclusion of a statement given in exchange for a promise not to prosecute for an additional crime. The court noted that such a holding would be in conflict with the well-established rule that the totality of the circumstances must be considered in.determining whether the confession was the result of overbearing by the police authorities. The court concluded that such a promise is merely one of the circumstances to determine whether the statement was freely and voluntarily given. Although the present case does not concern an admission given as a result of a plea [487]*487bargain agreement, the interrogating officer’s statement regarding the probable consideration of cooperation in determining the number of charges to be filed should likewise be merely one of the circumstances which determine whether the defendant’s statement was freely and voluntarily given.
A nonexhaustive list of potentially material considerations in determining the voluntariness of statements in the context of inducements by prosecuting authorities includes whether (1) defendant is in custody at the time of the statement, (2) defendant is alone and unrepresented by counsel, (3) the promise or inducement is initiated by prosecuting officials as opposed to defendant or someone acting on his behalf, (4) defendant is aware of his constitutional and other legal rights, (5) the potentially incriminating statement is part of an abortive plea bargain, (6) the promise or inducement leading to the statement is fulfilled by prosecuting authorities, and (7) defendant is subjected to protracted interrogation or evidence appears on the record to show that coercion precludes the statement from being knowing and intelligent. United States v. Williams, 447 F. Supp. 631 (D. Del. 1978). The Williams court concluded that the totality of circumstances must be examined in order to evaluate the voluntariness of an induced confession and that adherence to a per se suppression doctrine is unsatisfactory.
Tippitt v. Lockhart, 859 F.2d 595, 598 (8th Cir. 1988), concluded: “After considering the age and education of appellant, and the nature and extent of the interrogation, we conclude that the written confession given by appellant was the product of his rational and voluntary decision and that the officers’ promise did not coerce or overbear his free will.”
Upon the determination that the “however slight” rule is not a per se rule, it is apparent that whether a defendant’s statements resulted from an officer’s promise is a question of fact. We have said in the past that in reviewing the decision of the trial court in this respect, we will not reverse that decision unless it was clearly wrong and, on the other hand, that a finding that a confession was voluntarily made will not be overturned on appeal absent an abuse of discretion. See State v. Hall, 237 Neb. 169, 465 N.W.2d 150 (1991). These statements [488]*488laid side by side are obviously conflicting, but are simply repetitive of similar statements made in earlier cases.
We take this opportunity to set forth what we perceive to be the correct rule, and that is that a determination by the trial court that a statement was made voluntarily will not be disturbed on appeal unless clearly wrong. See State v. Lamb, 213 Neb. 498, 330 N.W.2d 462 (1983). See, also, State v. Hall, supra.
Although not cited as authority, the reasoning of Justice Boslaugh in his one-judge opinion State v. Muenchau and Brown, 209 Neb. 552, 308 N.W.2d 824 (1981), is quite compelling. He'states at 554,308 N.W.2d at 825-26:
At the suppression hearing, [Deputy] Marker testified that “John [Brown] was told the same thing that we tell anyone else that comes in. We cannot promise him that he will have a lighter sentence, that anything will happen, that normally when a person cooperates with the court, that the court takes that into consideration.”
The case State v. Smith, 203 Neb. 64, 66, 277 N.W.2d 441, 443 (1979), where a juvenile was told by an officer that “if the defendant cooperated with the police he would attempt to have the matter transferred to juvenile court,” was distinguished in the opinion of Justice Boslaugh. He said, “Here no such benefit was offered to the appellee in return for making a statement. The fact that the defendant had ‘cooperated’ by giving a statement to the deputy sheriff would be readily apparent to the county attorney.” 209 Neb. at 555,308 N.W.2d at 826.
Cited in State v. Muenchau and Brown, supra, was the case People v. Higgins, 50 Ill. 2d 221, 278 N.E.2d 68 (1972), cert. denied 409 U.S. 855, 93 S. Ct. 195, 34 L. Ed. 2d 100. We quote again the language of Justice Boslaugh from the Muenchau and Brown opinion:
In Higgins, the defendant and several other persons, including his sister, were arrested as suspects in the shooting death of a woman. In the course of a conversation with a police detective, defendant, in response to a question from the detective, asked: “ ‘If I tell the truth would you let the other people go? ’ Detective Davis answered that he had no authority to release anyone [489]*489who was arrested and charged and that only the State’s Attorney or judge could do so, but that, if defendant told the truth, the State’s Attorney would take this into consideration.” [Citation omitted.] The Illinois Supreme Court found that these remarks did not render defendant’s subsequent inculpatory statement involuntary.
209 Neb. at 555, 308 N.W.2d at 826.
In State v. Thomas, 232 Neb. 490, 441 N.W.2d 186 (1989), the defendant, after being read his rights, was told by the interrogating officer that he was facing a possible jail sentence and if the defendant revealed the source of the marijuana, there might be a possibility that.it could help him when he appeared in court. Although the defendant did not provide the name of the supplier to the police, he moved to suppress statements he made to officers on the basis that they were elicited by improper inducements. The court found that the officer’s comment that the revealing of the defendant’s source might possibly help him when he appeared in court did not warrant an overturning of the district court’s finding that the defendant’s statement was voluntarily made. Thomas is similar to the instant case in that the interrogating officer in Thomas said there was a possibility that revealing the source might help the defendant, and here, the interrogating officer said that the defendant’s cooperation would probably be taken into consideration as to how many cases were filed. In both cases the interrogating officers did not have authority to help the defendant, and neither officer made a promise of assistance, but speculated as to the effect of the defendant’s cooperation.
In State v. Porter, 235 Neb. 476, 455 N.W.2d 787 (1990), the primary interrogator told the defendant that it could help him if he confessed and that it would look better for him if he confessed. At one point the interrogator said that he was sure the judge would take that into consideration. The court held that the interrogator’s statements constituted implied promises of leniency which rendered the defendant’s confession involuntary. Porter is distinguishable from the case at bar in that the interrogator was sure that a statement would be taken into consideration, whereas in the case at bar the officer referred only to a probability of a reduction in the number of [490]*490cases filed.
Coercive police conduct is a necessary predicate to the finding that a confession is not voluntary within the meaning of the due process clause of the 14th amendment. State v. Hankins, 232 Neb. 608, 441 N.W.2d 854 (1989). There is no evidence of coercive police conduct in the present case.
After considering the age, education, experience, and mental capabilities of the defendant, and the nature and extent of the interrogation, we conclude that the trial court was not clearly wrong in concluding that the confession given by the defendant was the product of his rational and voluntary decision and that the officer’s rather innocuous statement that his report would indicate that defendant talked freely, which probably would be taken into consideration on how many cases were filed against him, did not coerce or overbear the defendant’s free will.
We deal next with defendant’s claim that the sentences imposed were excessive. Robbery is a Class II felony according to Neb. Rev. Stat. § 28-324 (Reissue 1989), which authorizes a maximum sentence of imprisonment of 50 years and a minimum sentence of 1 year. Attempted robbery is a Class III felony with a prescribed sentence of not more than 20 years nor less than 1 year. The sentences on the six robbery counts were respectively 5 to 10 years, 7 to 15 years, 9 to 20 years, 11 to 25 years, 15 to 50 years, and 15 to 50 years and on the attempted robbery, 6 to 15 years, with all sentences to run consecutively to each other. As earlier stated, these amounted to a total sentence of a minimum of 68 and a maximum of 185 years. The sentences imposed were within the statutorily prescribed limits.
As a general rule, a sentence imposed within the limits prescribed by statute will not be set aside as excessive absent an abuse of discretion. State v. Nevels, 235 Neb. 39, 453 N.W.2d 579 (1990). It is also within the trial court’s discretion to direct that sentences imposed for separate crimes be served consecutively. State v. Zaritz, 235 Neb. 599, 456 N.W.2d 479 (1990).
In imposing a sentence, a sentencing judge should consider the defendant’s age, mentality, education, experience, and social and cultural background, as well as his or her past criminal record or law-abiding conduct, motivation for the [491]*491offense, nature of the offense, and the amount of violence involved in the commission of the crime. State v. Nevels, supra. “Moreover, it is the minimum portion of an indeterminate sentence which measures its severity.” Nevels, supra at 53, 453 N.W.2d at 588. Thus the important prong of the sentence is the minimum sentence of 68 years. In light of the defendant’s age and insignificant prior criminal record, it is relevant to note that a sentence of imprisonment ought not exceed the minimum period consistent with protection of the public, gravity of the offense, and rehabilitative needs of the defendant. See State v. Sturm, 189 Neb. 299, 202 N.W.2d 381 (1972). Also, it is important to consider the rehabilitative needs of the defendant in sentencing, such as his or her addiction to narcotic drugs. One of the primary functions of the criminal law is to protect individuals and society from the depredations of the criminally bent. State v. Etchison, 188 Neb. 134, 195 N.W.2d 498 (1972).
It is difficult to color-match cases when reviewing the terms of sentences. Nevertheless, it is helpful to examine cases in which this court has reduced sentences.
In State v. Sturm, supra, the defendant, although admittedly abused by her husband, nevertheless waited until after he went to bed and had fallen asleep, and then she got a 12-gauge shotgun, loaded it with two shells, walked upstairs and into her husband’s bedroom, and fired a shot at him from a distance of 8 feet. When he bolted upright, she shot him again.
As stated in the dissenting opinion, in which two other justices joined, the county attorney saw fit only to charge the defendant with second degree murder. The jury saw fit to convict the defendant of manslaughter.
The penalty for manslaughter at that time was imprisonment for not less than 1 nor more than 10 years. The trial court imposed a flat sentence of 10 years, which in effect was 1 to 10 years. This court, although commenting on the lapse of time between the alleged violence against the defendant by her husband and the fact that she waited until he had gone to sleep before shooting him, also pointed to mitigating circumstances including the husband’s prior brutality and the defendant’s great emotional disturbance, and found the sentence to be excessive. The court reduced the sentence to 5 years, which [492]*492amounted to imprisonment for not less than 1 nor more than 5 years. The court further commented, “A sentence to imprisonment ought not exceed the minimum period consistent with protection of the public, gravity of the offense, and rehabilitative needs of the defendant.” State v. Sturm, supra at 302,202 N.W.2d at 382.
In State v. Foutch, 196 Neb. 644, 244 N.W.2d 291 (1976), the court reduced defendant’s sentence of 3 to 9 years’ imprisonment for assault with intent to inflict great bodily injury on a 4-year-old child to 1 to 3 years. The defendant, the boyfriend of the child’s mother for a period of 1 year, kicked the child for disobedience. As a result of the kick the child fractured his leg when either an electric fan fell on him or he was kicked into the fan. The court noted that defendant was 26 years of age with no prior record and that he did not represent a threat to the community.
State v. Burkhardt, 194 Neb. 265, 231 N.W.2d 354 (1975), involved a sentence of imprisonment of from 2 to 6 years for grand larceny which was reduced to a term of 1 to 3 years. The defendant’s accomplice received 2 years’ probation. The defendant was 19 years of age, his accomplice 18 years old, and neither had aprior felony record, but both had juvenile records. The defendant, unlike his accomplice, had a history of drug use.
The defendánt in State v. Stuggett, 200 Neb. 693, 264 N.W.2d 876 (1978), had been sentenced to a term of imprisonment of 30 years for second degree murder, which was reduced by this court to 15 years. The conviction arose out of a fight in which the victim struck the defendant, who then retaliated by stabbing the victim in the chest three times. The court found the murder, although serious, was unplanned and provoked by the victim. The court concluded that the reduction of the sentence from 30 years to 15 years was consistent with protection of the public, gravity of the offense, and rehabilitative needs of the defendant.
This court has no Ouija board, nor do we possess any degree of prescience beyond that of sentencing judges. However, we do have the benefit of examination of sentences from many courts throughout this state for a variety of crimes and under diverse [493]*493circumstances, in which no opinions are written or published. Realizing, as we have stated, that a sentence ought not be longer than is necessary for rehabilitation and protection of society and that it is the minimum portion of an indeterminate sentence which measures its severity, we find that the minimum term of 68 years is substantially more than is necessary for rehabilitative purposes, is an obstacle so as to discourage the defendant from attempting rehabilitation, and is more than is necessary for the protection of society. To that extent the sentences constitute an abuse of discretion.
Based on the foregoing facts, law, and reasoning, we modify the judgment of the district court to provide that the defendant shall be sentenced to serve terms of imprisonment in an institution under the control of the Department of Correctional Services of 5 to 10 years on each of counts I, II, III, and IV, to be served consecutively to each other; of 5 to 25 years on each of counts V and VI, to be served concurrently with each other, but consecutively to the sentences on counts I, II, III, and IV; and of 5 to 15 years on count VII, to be served consecutively to the sentences on counts I to VI. This reduces the total of the sentences to a term of not less than 30 nor more than 80 years.
The judgment of the district court, as so modified, is affirmed.
Affirmed as modified.