The sole issue in this appeal is whether the district court abused its discretion in sentencing Gregory Storey for the crimes of robbery and battery committed with the use of a firearm. The robbery resulted in a fixed life sentence. The battery sentence, enhanced because a firearm was used, totalled thirty years — also fixed— running concurrently with the life sentence. We affirm these sentences.
The circumstances of these crimes need only be reviewed briefly. Late in the afternoon of July 9, 1981, the victim was about to retrieve his car from a parking garage in Boise, Idaho. As he was walking up the staircase he was shot twice in the back of the head, once in the neck as he turned around to confront his assailant, and a fourth time after he fell to the floor. The final shot, aimed at the victim’s head, lodged in the victim’s wrist as he raised his arm to protect himself. The victim’s wallet and checkbook were taken and his assailant fled the scene. While the victim was still conscious, he was found by a passerby. Assistance was rendered and the police were summoned. The victim was able to give police an identification of his assailant before being transported to the hospital. It was determined that the victim’s wounds were caused by .22 caliber bullets. Despite his injuries, the victim survived.
Approximately one hour after the shooting, police came upon Storey walking along the street. His description matched that of the assailant. Storey was stopped and searched. A .22 caliber pistol was found in his pocket. Four rounds had been fired. Storey was arrested for carrying a concealed weapon. The police also searched Storey’s backpack and found the victim’s wallet and checkbook. Storey was taken to police headquarters and questioned. He denied shooting anyone. He admitted the gun was his, but claimed he had left it home that day. He did not know how it came to be upon his person. Nor could he explain how the victim’s wallet and checkbook came into his possession. The victim identified Storey as the assailant. On July 30, Storey was charged with robbery, I.C. § 18-6501; with battery with intent to commit murder and/or robbery, I.C. § 18-911; with use of a firearm during the commission of the battery, I.C. § 19-2520; and with carrying a concealed weapon. Storey *995was bound over to the district court for trial and pled not guilty.
Storey, through his attorney, filed notice of intent to rely upon mental disease or defect. An order for evaluation of mental condition was entered pursuant to I.C. § 18-211, and Storey was transferred to the Security Medical Facility at the Idaho State Correctional Institute. He was diagnosed as having a “major mental disease of a schizophrenic type with paranoid features.” The psychiatrist concluded that Storey was “unable to aid in his defense or appreciate the wrongfulness of his conduct.” Based on the evaluation, the trial court held that Storey was unable to assist in his defense and therefore lacked fitness to proceed with trial. On January 6, 1982, Storey was committed to the Department of Health and Welfare for treatment, including the forceful administration of drugs. The trial date was vacated until such time that it was determined he could stand trial.
An updated report was filed in March of 1982 concluding that Storey's mental condition had improved to the point where he was then able to stand trial. At that time Storey’s counsel moved for a judgment of acquittal.1 The motion was denied and trial commenced on July 12, 1982. The jury rejected the mental illness defense proffered by Storey. He was convicted on all counts. In November, the district judge sentenced Storey to serve a fixed life term of imprisonment for robbery. Storey also received a fixed term of fifteen years for battery with intent to commit a serious felony. Because the jury specifically found that a firearm was used in the commission of the battery, the court enhanced the sentence by an additional fixed term of fifteen years. I.C. § 19-2520. The thirty year battery sentence was made to run concurrently with the life sentence for robbery. Finally, Storey received a concurrent term of six months for carrying a concealed weapon. Storey filed notice of appeal, but also moved for reconsideration of the sentences under I.C.R. 35. After a hearing, the district court denied the motion. The issue raised on appeal is whether the sentences imposed are excessive.
Here, each sentence the trial court imposed was the maximum penalty. See I.C. §§ 18-912, 19-2520, 18-6503. The sentencing judge chose to impose fixed sentences rather than indeterminate sentences. I.C. §§ 19-2513, -2513A. The length of a sentence to be imposed is generally within the sound discretion of the trial court. State v. Major, 105 Idaho 4, 665 P.2d 703 (1983). If a sentence is within the statutory maximum it will not be disturbed on appeal absent a clear showing of an abuse of discretion. State v. Cotton, 100 Idaho 573, 602 P.2d 71 (1979). To prevail on excessiveness grounds, i.e., to show an abuse of discretion, the defendant must show that the sentence is unreasonable considering the particular facts of the case. State v. Toohill, 103 Idaho 565, 650 P.2d 707 (Ct.App.1982). A sentence is unreasonable if it exceeds the minimum sentence necessary to achieve the primary purpose of sentencing — protection of society — and the related goals of deterrence, rehabilitation or retribution. Id.
We will first consider the fixed life sentence for robbery. A person serving a fixed life sentence is never eligible for parole consideration. State v. Rawson, 100 Idaho 308, 597 P.2d 31 (1979). Nor is good time available to him. I.C. § 20-101A. He is in fact sentenced to the Board of Correction for the remainder of his natural life unless the sentence is commuted or he is pardoned. The question then is whether the fixed life sentence was necessary to accomplish the sentencing objectives outlined in Toohill.
At the sentencing hearing, the district judge noted the severity of the offense, *996saying it was the most aggravated robbery situation he ever had to confront. Because of the irrational nature of the offense, he concluded the protection of society was his primary concern. The record leaves little doubt — indeed it is undisputed — that an untreated chronic mental illness was a significant factor in the commission of these crimes.
At the hearing on defendant’s motion to reconsider, Storey called a psychologist, a clinical psychologist and a senior social worker, all of whom had had contact with Storey at the Idaho State Correctional Institution since the trial. Each testified that the medication program maintained for Storey had made positive changes in his personality and behavior. They each believed that with continued supervision and medication Storey would present little risk of repeating the dangerous, irrational behavior that surfaced at the time of the crime. The district court considered the rehabilitation purpose of sentencing. However, the district judge felt that the possibility of rehabilitation was not enough. He concluded that because of the circumstances of the crime with its manifested attempt to take a life, Storey posed an undue risk to society. Not without reason, the judge believed Storey could never be safely readmitted into society. Therefore, the judge felt compelled to impose the maximum sentence. He told Storey that “if the doctors are correct... and you can be rehabilitated and ... you can be released with safety, then, of course, the Board2 has the power of commutation at a later time, but I think ... I have to sentence you as I find you at this point.”
We have carefully examined the facts and the record in this case and believe several factors support the district court’s decision. First, the seriousness of the offense: The attack was unprovoked upon a victim apparently chosen at random. It was an execution-style attempt to take a human life. Only fortuitously was it unsuccessful. Second, the mental state of Storey: Storey has always denied that he committed the offense. He argues instead that the evidence was planted on him by “conspirators.” The presentence report suggested no other alternative but long-term treatment during incarceration, so that Storey will be unable to present a further threat to society. Third, there is the possibility that another act like this may occur if Storey is not under continuous supervision to assure that stabilizing medication would be administered regularly. Considering Storey’s lack of family and other supportive resources, plus his denial of any mental disease and of any need for treatment, an indefinite period of incarceration was not unreasonable. The sentence imposed was justified to protect society from Storey’s dangerous, erratic behavior. This is a sufficient basis for upholding the sentence. Therefore, we affirm the fixed life sentence for robbery.
Appellant contended at oral argument that the fixed life sentence for robbery was enhanced by a consecutive fixed sentence of fifteen years for use of a firearm. The “Judgment of Conviction” entered in this case, standing alone, could lead to such a belief. The judgment is not clear. Only when the information and the verdict forms are examined is it clear that the jury specifically found that the firearm was used in the commission of the battery. From the record it is apparent that the sentencing judge intended to enhance the fifteen-year sentence for battery by an additional fifteen-year sentence for use of a firearm. I.C. §§ 18-911 and 19-2520. Therefore, we will review the sentences for excessiveness, construing them as the judge intended.
As we have previously noted, a fixed fifteen-year sentence for battery, enhanced by an additional fifteen years for use of a firearm, represents the maximum sentence which the law allows for this crime. However, the sentence is consistent with the sentence imposed for the robbery. *997In our view the same reasons for affirming the robbery sentence are applicable to the battery sentence. Therefore, we do not believe this sentence, standing alone or in combination with the other sentences, is excessive.
When a judgment of conviction contains the sentence, it must show clearly on its face the sentence imposed and, if more than one sentence is involved, it should show clearly how those sentences relate to each other. We believe it is necessary for the district court to correct the judgment of conviction entered in this case to more clearly set forth the sentence imposed for the battery. We consider this to be a mere clerical error which can be corrected under I.C.R. 36 when the case has been remanded. See e.g. State v. Greensweig, 102 Idaho 794, 641 P.2d 340 (Ct.App.1982).
For guidance to sentencing judges, we repeat what we first said in State v. Kaiser, 106 Idaho 501, 681 P.2d 594 (Ct.App.1984) vacated on other grounds, 108 Idaho 17, 696 P.2d 868 (1985). “We think I.C. § 19-2520 must be construed so that the underlying sentence and the enhancement sentence can be viewed as one continuous sentence with two distinct segments.” 106 Idaho at 503, 681 P.2d at 596. “When a sentence is enhanced under I.C. § 19-2520 each segment should, of course, be separately pronounced and set forth in the judgment of conviction and commitment so that the propriety of either component of the sentence can be determined in the event of any judicial review of the sentence.” 106 Idaho at 504, 681 P.2d at 597.
We note another matter of more significance which has not been raised directly on appeal or argued to us. It involves the sentence imposed for battery. The acts charging the commission of battery in Count I of the information are the identical acts charged in Count II of the information as the means by which the robbery was accomplished with force. This suggests that the battery must be construed to be an included offense within the robbery charge. See e.g. State v. Thompson, 101 Idaho 430, 614 P.2d 970 (1980); State v. Blacksten, 86 Idaho 401, 387 P.2d 467 (1963); Bates v. State, 106 Idaho 395, 679 P.2d 672 (Ct.App.1984). The constitutional prohibition against double jeopardy bars conviction and punishment for included offenses. If there is a double jeopardy problem, then the battery charge should have been dismissed. No sentence should have been entered upon the conviction for that charge. Because neither party addressed this problem in our court, we will not decide the issue. We merely note that on remand Storey will have the opportunity to present this issue to the district court by way of a motion under I.C.R. 35 to correct or modify the sentence. Thus, the district court can deal with both problems relating to the sentences at the same time.
. Until July 1, 1982, former I.C. § 18-213 permitted a trial judge to enter a "judgment of acquittal on the ground of mental disease or defect excluding responsibility” if, on the basis of reports filed, the court was satisfied that, at the time of the crime, the defendant’s "capacity to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of the law,” was "substantially impaired."
. Under art. 4, § 7 of the Idaho Constitution and I.C. § 20-211 and -213, the Board of Correction, acting through the Commission of Pardons and Parole, has the power to commute fixed sentences. See State v. Rawson, supra.