JUSTICE McLAREN delivered the opinion of the court:

Defendant, James K. Santos, appeals his conviction of theoffense of aggravated criminal sexual abuse in that he, over 17years of age, penetrated the vagina of the victim, T.K., at leastage 13 but less than 17 years old, with his penis, and he was atleast 5 years older than the victim. 720 ILCS 5/12-16(c) (West1998). We reverse and remand.

The charges against defendant arise from an incident thatoccurred during the early morning hours of May 9, 1999. At thistime, defendant is alleged to have penetrated the vagina of T.K.,who was between the ages of 13 and 17, while he was over 17 yearsof age and at least 5 years older than T.K. In his defense,defendant asserted that, while having sexual intercourse with T.K.,she told him for the first time that she was 16 years old, at whichtime he immediately ceased the sexual activity.

Prior to trial, defendant filed a motion in limine seekingpermission to cross-examine the victim regarding inconsistentstatements she made during the investigation. The motion assertedthat T.K. submitted to a rape kit and denied to hospital personnelany sexual activity within 72 hours of the alleged assault. Afterit was determined that seminal fluid and pubic hair were found inT.K.'s underwear, she admitted to police that she had had a sexualencounter with a third party within 72 hours of the allegedassault. Defendant sought to introduce evidence of T.K.'scontradictory statements to impugn her credibility. In response,the State filed a motion in limine to prohibit defendant frommaking any reference to T.K.'s past sexual activity or reputationpursuant to the rape shield statute. 725 ILCS 5/115--7(a) (West1998).

The trial court ruled that the rape shield statute prohibitedthe admission of the evidence proposed by defendant. Defendant wasprohibited from cross-examining the victim concerning theinconsistent statements she made to hospital personnel and thepolice.

The State's main witness was the victim, T.K. On May 9, 1999,she was 16 years old. On May 8, 1999, she purchased a fifth or ahalf-gallon of vodka and arrived at the home of Jason Ganus at 7 or8 p.m. T.K. consumed vodka and orange juice with friends for oneor two hours. The group left the Ganus home when Jason's parentsintervened.

T.K. and a female friend walked to the home of Angie Enna, a25-year-old woman who lived in a housing complex known as theFairgrounds. There were several other persons present, including defendant. T.K. accompanied defendant to a liquor store, wherethey obtained more alcohol.

The group returned to the party and consumed more alcohol. When defendant asked T.K. her age, she stated that she was 16. T.K. and defendant drove around Rockford for four or five hours indefendant's car. They pulled into a driveway of a home in aresidential area and began to kiss. T.K. informed defendant thatshe wanted to go back to the party because she did not feel well. Defendant and T.K. began to drive around in defendant's car, anddefendant pulled into a parking lot.

Defendant began to kiss T.K. When T.K. stated that she didnot want to kiss, defendant grabbed her shoulder and "yanked" herfrom the passenger seat into the backseat. Defendant grabbed herarms and tried to kiss her. When she protested, defendant saidthat he thought she "wanted this" and pulled her pants down.

T.K. screamed as defendant removed her pants and underwear. He thrust his fingers inside of her vagina. He removed his ownpants and attempted to place his penis inside her vagina. Whendefendant placed his penis into T.K.'s vagina, she pushed him offher. They returned to the front seat, got dressed, and drove to anAmoco gas station, where T.K. threw up. Defendant washed his car,and he and T.K. returned to the party at the Fairgrounds. T.K. didnot report the attack to anyone at the Amoco station, call forhelp, or attempt to flee the scene.

T.K. was examined in the Rockford Memorial Hospital emergencyroom by Chrislyn Senneff, R.N., and Dr. Aldred. Nurse Senneffobserved an abrasion to T.K.'s cheek that appeared to be new and anabrasion to her buttocks. She did not note any vaginallacerations. T.K. told nurse Senneff that defendant penetrated herrectum with his fingers.

America Smith testified that she was "hanging out" at theFairgrounds party. When America and her boyfriend, Joe Ferguson,went to a gas station at midnight, T.K. was sitting in defendant'scar listening to the radio. At approximately 5 a.m., America wasawakened when T.K. and defendant returned to the party. T.K. wascrying. T.K. told America and a friend, Tiffany Reaves, that shehad been raped.

Rockford police officer Rose Mary Mathews testified that shewas called to the Rockford Memorial emergency room on May 9, 1999,regarding a sexual assault. Mathews took photographs of a scratchon T.K.'s jaw.

Officer Walter Felton of the Rockford police departmenttestified that he spoke to defendant on May 18, 1999. Defendanttold Officer Felton that T.K. informed him she was 18 years old onthe night in question. While they were engaged in sexualintercourse, T.K. told defendant she was 16 years old. Defendantwas born on December 19, 1964.

Defendant testified in his case in chief. On May 8, 1999, heattended a party at the Fairgrounds housing complex. T.K. waspresent. Defendant was not previously acquainted with T.K.

Defendant took T.K. and some other persons at the party to aliquor store. T.K. told defendant she was 18 years old. Afterobtaining alcohol from a liquor store and consuming it at theparty, T.K. asked defendant if she could go for a ride with him.

T.K. and defendant drove around in his car listening to music. They consumed more alcohol. T.K. leaned over to defendant andkissed him. Defendant parked the car in a residential area andbegan kissing T.K. T.K. grabbed at defendant's leg and touched hispenis through his clothing, and he fondled her breasts. Thisactivity lasted for approximately 15 to 20 minutes.

T.K. voluntarily climbed into the backseat of defendant's car. Defendant joined her in the backseat, where they kissed and fondledeach other. When T.K. tugged at defendant's pants in an attempt tounfasten them, defendant undressed. T.K. undressed herself. Whendefendant inserted his penis in T.K.'s vagina, she said to stop. Defendant stopped immediately and denied that there was a struggle. At this point, T.K. told defendant she was 16 years old. Defendantstated that, if he had known T.K. was 16 years old, he would nothave touched her. Defendant also denied placing his fingers inT.K.'s vagina or rectum.

After the incident, T.K. and defendant drove around in hiscar. While at an Amoco station, T.K. vomited. Defendant purchaseda soda for T.K. When he returned, she was no longer in hisvehicle. Defendant found T.K. at the National Pride Car Wash. Shevoluntarily entered his vehicle, and they returned to theFairgrounds party. T.K. went upstairs with America Smith. AfterJoe Ferguson went upstairs, he told defendant that T.K. stateddefendant tried to rape her.

The jury was given the following issues instruction on thecharge of aggravated criminal sexual abuse, without objection bydefendant:

"To sustain the charge of aggravated criminal sexualabuse involving penetration, the State must prove thefollowing propositions:

First Proposition: That the defendant committed an act ofsexual penetration upon T.K.; and

Second Proposition: That T.K. was at least 13 years ofage but under 17 years of age when the act was committed; and

Third Proposition: That the defendant was at least fiveyears older than T.K.

If you find from your consideration of all the evidencethat each of these propositions has been proved beyond areasonable doubt, you should find the defendant guilty.

If you find from your consideration of all the evidencethat any one of these propositions has not been proved beyonda reasonable doubt, you should find the defendant not guilty."

See Illinois Pattern Jury Instructions, Criminal, No. 11.62A (4thed. 2000) (hereinafter IPI Criminal 4th).

The jury found defendant guilty of aggravated criminal sexualabuse involving penetration and proof that the victim was betweenages 13 and 17 while defendant was at least 5 years older. 720ILCS 5/12--16(c) (West 1998). Defendant was found not guilty of theremaining charges of criminal sexual assault (720 ILCS 5/12--13 (a)(West 1998)) and aggravated criminal sexual abuse involving sexualconduct and the use of force (720 ILCS 5/12--16(c)(1)(ii) (West1998)). Defendant was sentenced to a term of four years in prison.

We first address defendant's contention that he was denied afair trial because the issues instruction posed to the jury did notreference the State's burden of proving that defendant could nothave reasonably believed T.K. was 17 or older. Defendant did notobject to the issues instruction when it was offered, present analternate instruction, or raise this issue in his posttrial motion. To preserve an argument for appeal, both an objection at trial anda written posttrial motion raising the issue are required. Peoplev. Enoch, 122 Ill. 2d 176, 186 (1988). The failure to object to ajury instruction waives the issue for appeal. People v. Booker,224 Ill. App. 3d 542, 555 (1992). Defendant has waivedconsideration of this issue because he did not object to thisinstruction when it was given or raise this allegation of error inhis posttrial motion.

Under the plain error exception to the waiver rule (177 Ill.2d R. 451(c)), substantial defects in jury instructions in criminalcases may be reviewed by the court despite the failure to make atimely objection, if the interests of justice require. People v.Thurman, 104 Ill. 2d 326, 329 (1984). The plain error exception tothe waiver rule permits a reviewing court to consider issuesotherwise waived where (1) the evidence in a criminal case isclosely balanced or (2) the error is so fundamental and of suchmagnitude the accused was denied a fair trial. People v. Lucas,151 Ill. 2d 461, 482 (1992); 134 Ill. 2d R. 615(a).

Certain instructions, such as the elements of the offense andthe issues instruction, are essential to a fair trial. The failureto give such instructions constitutes grave error when, viewing therecord as a whole, it appears that the jury was not adequatelyapprised of the State's burden of proof. People v. Reddick, 123Ill. 2d 184, 198 (1988). In our view, the evidence in this casewas closely balanced. The failure to proffer an issues instructionthat properly delineated the State's burden of proof, under thecircumstances, constitutes plain error. Therefore, we will reviewthe issue raised by defendant on the merits.

The purpose of jury instructions is to guide the jury in itsdeliberations and to help it reach a proper verdict through the application of legal principles to the evidence. People v. Banks,287 Ill. App. 3d 273 (1997). Every litigant is entitled to havethe jury instructed on the law governing the case. Malek v.Lederle Laboratories, 125 Ill. App. 3d 870, 872 (1984). Theinstructions must be sufficiently clear so as not to confuse ormislead the jury. Malek, 125 Ill. App. 3d at 872.

According to Supreme Court Rule 451(a) (177 Ill. 2d R.451(a)), juries in criminal cases must be instructed pursuant tothe Illinois Pattern Jury Instructions unless the court determinesthat the particular instruction does not accurately state the law. See People v. Haywood, 82 Ill. 2d 540, 545 (1980); People v.Testin, 260 Ill. App. 3d 224, 230 (1994). A defendant is entitledto an instruction on his theory of the case if there is somefoundation for the instruction in the evidence. If there is suchevidence, it is an abuse of discretion for the trial court torefuse to so instruct the jury. People v. Crane, 145 Ill. 2d 520,526 (1991). Very slight evidence upon a given theory of a casewill justify the giving of an instruction. People v. Moore, 250Ill. App. 3d 906, 915 (1993).

Here, defendant claimed, as an affirmative defense to thecharge of aggravated criminal sexual abuse, that he reasonablybelieved T.K. was 17 years old or older. To avail himself of thisaffirmative defense, defendant was required to produce someevidence at trial to demonstrate the existence of such a reasonablebelief. See People v. Kite, 153 Ill. 2d 40, 44-45 (1992).

Not only did defendant present evidence in support of hisaffirmative defense, but the State also presented evidencesufficient to raise this issue. At the time of the offense, T.K.was 16 years old and defendant did not know T.K. prior to theincident. T.K. was consuming alcohol when defendant met her; shewas at the apartment of a 25-year-old woman in the early morninghours; and she seemed free to stay either overnight or out untilthe early morning hours. Additionally, the jury heard conflictingevidence from defendant and T.K. as to T.K.'s statements concerningher age prior to the sexual contact. Therefore, defendant wasentitled to have the jury instructed on this affirmative defense.

Although a separate instruction on the affirmative defense wasgiven (IPI Criminal 4th No. 11.64), the issues instruction givendid not reference the State's burden to disprove the affirmativedefense. The committee notes to the issues instruction foraggravated criminal sexual abuse (IPI Criminal 4th No. 11.62A)state that, when a defendant is charged with this offense (720 ILCS5/12--16(d) (West 1998)) and the defendant's defense that hereasonably believed the victim to be 17 or 16 years of age or olderis raised by the evidence, the following instruction should begiven as the final proposition:

"Fourth Proposition: That the defendant did notreasonably believe [T.K.] to be [(16) (17)] years of age orolder." IPI Criminal 4th No.11.62A, Committee Note, at 565.

The issues instruction given to the jury did not contain thisfourth proposition. Thus, the jury was not advised that, toconvict defendant of the offense of aggravated criminal sexualabuse, the State had to prove beyond a reasonable doubt that he didnot have a reasonable belief that T.K. was 17 years of age orolder. By omitting the fourth proposition, the jury was notproperly apprised of the State's burden of proof. Therefore, wedetermine that the failure to provide a proper issues instructionconcerning the State's burden of proof for the offense ofaggravated criminal sexual abuse deprived defendant of a fairtrial. Therefore, we reverse defendant's conviction of aggravatedcriminal sexual abuse and grant defendant a new trial on thischarge. Due to our determination on this issue, it is unnecessaryto address the issue of whether the State proved defendant guiltyof the offense of aggravated criminal sexual abuse beyond areasonable doubt, except for the purposes of double jeopardy. People v. Daniels, 187 Ill. 2d 301, 310 (1999). For this purpose,we determine that any rational trier of fact could have found theessential elements of the offense beyond a reasonable doubt. Thetestimony of the complainant, if believed, would have sustained theconviction.

In his brief, defendant contends that the trial court erred inexcluding evidence of T.K.'s inconsistent statements concerningwhether she had sexual intercourse with anyone other than defendantwithin 72 hours of submitting to a rape kit pursuant to the rapeshield statute (725 ILCS 5/115--7 (West 1998)). We will addressthis issue on the merits since it is likely to arise at retrial.

The rape shield statute provides that, in prosecutions foraggravated criminal sexual abuse, when the commission of theoffense involves sexual penetration or sexual conduct, the priorsexual activity or the reputation of the alleged victim isinadmissible except as evidence concerning the past sexual conductof the alleged victim with the accused when the evidence is offeredby the accused on the issue of consent or the evidence isconstitutionally required to be admitted. 725 ILCS 5/115--7(a)(West 2000). Defendant contends that evidence of T.K.'scontradictory statements to emergency room personnel and to thepolice concerning sexual contact with someone other than defendantwithin 72 hours of submitting to a rape kit was relevant to impugnthe credibility of T.K.'s testimony that she informed defendantprior to the alleged assault that she was 16 years old. He assertsthat such evidence should have been admitted under theconstitutional exception to the rape shield statute.

In People v. Grano, 286 Ill. App. 3d 278 (1996), weinterpreted the parameters of the rape shield statute. There, wedetermined that the statute was not designed to preclude theadmission of all evidence related to sex. Instead, the legislativeintent of the rape shield statute is to exclude evidence of actualsexual history or reputation of the victim, not evidence offeredfor the purpose of impeachment, even when that evidence relates tosex. Thus, in Grano, we held that the trial court improperlyexcluded evidence proffered by the defendant that the victim of analleged sexual assault made prior inconsistent statementsconcerning sexual relations with adult men other than the defendantwhen that evidence was offered for the purpose of impeaching thevictim's credibility on a material issue.

Under the rationale of Grano, the rape shield statute does notprohibit the introduction of evidence concerning T.K.'s inconsistent statements to emergency room personnel and the policeconcerning sexual contact with a person other than defendant. Theoffense at issue was aggravated criminal sexual abuse, in thatdefendant, being over the age of 17, penetrated the vagina of T.K.,who was between the ages of 13 and 17, and defendant was at least5 years older than T.K. Defendant raised the affirmative defenseof his reasonable belief that T.K. was over the age of 17, andthere was conflicting evidence on this issue. Defendant testifiedthat, before his sexual encounter with T.K., she told him that shewas 18 years old; he said he first learned she was 16 years oldonly after she stated that during the penetrating act. Incontrast, T.K. testified that she told defendant she was 16 yearsold before the sexual encounter. Due to the nature of the evidencerelating to defendant's affirmative defense, T.K.'s credibility wasat issue. Accordingly, the trial court misapplied the rape shieldstatute as a basis for excluding the evidence of T.K.'sinconsistent statements to the emergency room personnel and to thepolice. On remand, a limiting instruction to the jury should begiven that it is to consider evidence of T.K.'s inconsistentstatements not as evidence of sexual activity or reputation but asevidence of the credibility of her testimony.

The portion of the judgment of the circuit court of WinnebagoCounty finding defendant guilty of the offense of aggravatedcriminal sexual abuse is reversed, and the cause is remanded for anew trial on this charge.

The judgment of the circuit court of Winnebago County isreversed, and the cause is remanded.

Reversed; cause remanded.

BYRNE, J., concurs.

JUSTICE O'MALLEY, specially concurring in part and dissentingin part:

I agree that a new trial is necessary because the issuesinstruction did not apprise the jury of the State's burden todisprove the defendant's affirmative defense that he reasonablybelieved T.K. was 17 years old or older. However, upon furtherreflection prompted by the petition for rehearing, I must dissentfrom the anticipatory discussion of the admissibility of T.K.'scontradictory statements to emergency room personnel regardingwhether she had sexual intercourse with anyone other than defendantwithin 72 hours of submitting to a rape kit. Citing Grano as itssole authority, the majority accepts the defendant's argument thatthese statements are admissible "under the constitutional exceptionto the rape shield statute" to "impugn the credibility of T.K.'stestimony that *** she was 16 years old." Slip op. at 11.

My first dispute is with the majority's interpretation ofGrano. The majority states that Grano "held that the trial courtimproperly excluded evidence proffered by the defendant that thevictim of an alleged sexual assault made prior inconsistentstatements concerning sexual relations with adult men other thanthe defendant." Slip op. at 12. This is not correct. The defensein Grano did not seek to introduce any "prior inconsistentstatements" by the victim. A statement by a witness is admissibleas a prior inconsistent statement only if it has the tendency tocontradict the witness's trial testimony. People v. Zurita, 295Ill. App. 3d 1072, 1077 (1998). The defense in Grano sought tointroduce testimony from other witnesses that the victim "madeprior allegations of sexual activity with other men and that suchactivity never occurred." Grano, 286 Ill. App. 3d at 287. Thedefense proposed to do this through "three witnesses who wouldtestify that the victim told them that she had sex with three otheradult men, and three witnesses (the other adult men) who wouldtestify that they never had sex with the victim." Grano, 286 Ill.App. 3d at 287-88. There was no indication in Grano that thetestimony offered by the defense had the tendency to contradict thevictim's trial testimony. The court did not analyze the testimonyas a prior inconsistent statement but as a prior false allegationof sexual activity. See Grano, 286 Ill. App. 3d at 288-89.

My second point is that if the majority, in citing Grano,presupposes that the contradictory statements of the victim offeredby the defense in this case will be admissible on remand as "priorinconsistent statements" simply because the contradiction in thestatements might undermine T.K.'s credibility, the majority ismistaken. T.K. made two out-of-court statements that contradictedeach other, but, as far as the record shows, neither statement hadthe tendency to contradict her trial testimony. Neither statementwill be admissible on remand as a prior inconsistent statementunless it has the tendency to contradict T.K.'s trial testimony.

Last, I see no means available for using either of T.K.'sstatements to attack her credibility other than as a priorinconsistent statement (provided, of course, that the statementwould have a tendency to contradict her trial testimony). The factthat T.K. made contradictory statements outside court is by itselfno basis for a general assault on her credibility. "In Illinois,it is well settled that the proper procedure for impeaching awitness' reputation for truthfulness is through the use ofreputation evidence." People v. West, 158 Ill. 2d 155, 162 (1994). In the wake of West, the appellate court has held that specificinstances of untruthfulness are not admissible to attack awitness's believability. See People v. Morrow, 303 Ill. App. 3d671, 680 (1999); People v. McGee, 286 Ill. App. 3d 786, 796 (1997). If the record on remand does not provide a basis for the admissionof either statement as a prior inconsistent statement, thecontradiction in the statements will remain a specific out-of-courtinstance of untruthfulness and, accordingly, inadmissible.