What she believes was allowed to happen during the Pinnacle High School homecoming dance last year haunts Heidi Peterson.

The Phoenix Police Department was called in to investigate allegations of a sexual assault against a special-needs student. That student was Heidi Peterson's 16-year-old daughter.

After 12 News began asking questions about how this could have happened during a school function, attempts were made to transfer the child to another school in the district.

Early on, after we tried to talk to one school employee, we were told by Anna Lieggi-Nadler, the Paradise Valley Unified School District director of marketing and communications, that we were not to go to the homes of the employees who became witnesses seeking comment. We were instead told to request formal interviews through her office.

We submitted a request for on-camera interviews with Pinnacle High School Principal Troy Bales, Assistant Principal Heather Brelow and three special-education teachers who were later interviewed during the Phoenix Police Department investigation. Our request for interviews was flatly denied.

A mother's worst nightmare

As a general rule, Peterson says she never lets her daughter out of her sight. The teen is developmentally disabled and is a special-needs students at Pinnacle High School in Phoenix. Though not autistic, she's currently in the autism program.

With Saturday, Oct. 11 around the corner, Peterson was faced with a difficult decision of whether to let her go to the homecoming dance.

Peterson reluctantly agreed, and emails between Peterson and Shelley LeValley, the girl's teacher, show LeValley would be there to support any students who chose to attend.

Peterson says she was given to understand that between LeValley and her daughter's teacher from the prior year, Melissa Lane-Isaksson, the special-needs students would be chaperoned throughout the dance.

"I couldn't have asked for a better situation to have happened," said Peterson.

In fact, LeValley had communicated with Peterson the week leading up to the dance. Emails describe efforts to find the perfect dress for the occasion, which would also be the day the girl turned 16.

"What a fun way to spend her 16th birthday!" LeValley wrote. "She was so excited to go shopping with you tonight. Very special mom and daughter time! Brings back great memories of those times with my mom."

"I spent all day doing her makeup and her hair and buying shoes and all the dress shopping and I wanted her to have that experience," said Peterson.

LeValley would escort Peterson's daughter and another of her students into the dance. LeValley would later tell police she told the girl to have fun and told her where she would be if she needed anything.

That night, LeValley and Lane-Isaksson were assigned as chaperones, while fellow special-education teacher Jennifer In-Albon was assigned to watch who left the gym.

In all, records supplied to us by the Paradise Valley School District show the dance was chaperoned by more than 35 members of Pinnacle's faculty and staff, along with two Phoenix police school resource officers.

Panic sets in

When Peterson arrived to pick up her daughter shortly before 11 p.m., she was nowhere to be found.

"I was thinking, you know what, she'll be the last girl out of there because finally she got her night and she's been having fun," said Peterson. "She'll be bouncing off the ceiling when she gets out of there, they'll have to drag her out."

Instead, her daughter didn't come out at all and Peterson couldn't find her. She would enlist the help of anyone she could find outside the gym and repeatedly call the cell phone she placed in her daughter's purse for about 30 minutes with no answer.

When she finally answered, she told her mother she was at their car in the parking lot.

"Oh thank God, thank God, I couldn't even imagine what I later find out," said Peterson.

Eager to hear how her night went, she thought it odd her daughter sat in the back of her SUV. She told her to move up front.

"I couldn't wait, I couldn't wait to hear everything and I couldn't wait to hear about her first time at a dance," Peterson said.

But those details never came. Instead Peterson says her daughter sat in silence. It was dark outside, but the overhead parking lights revealed to Peterson her daughter had dirt on her face, dirt in the cracks of her lips, scraped knees and was missing her school badge.

"I asked her, straight out, 'Were you raped?'" Peterson said. She says her daughter didn't say a word.

Peterson says she took her daughter straight to Assistant Principal Heather Brelow and shared her concerns. Phoenix police were called to the school. Peterson says Principal Troy Bales stood across the street while Brelow talked to police.

A police report shows Brelow told Officers Linda Herrin and Ruben Ruiz that the girl told her she left the dance with a boy and walked around the corner and "humped." Brelow told the officers the girl is in special education and is "low functioning."

One of the officers asked the girl what she meant by "humped" and she replied, "I don't know."

Police conduct sexual-assault investigation

Phoenix police would launch an investigation into the alleged sexual assault during the dance. Peterson's daughter was taken to the Family Advocacy Center and given a forensic medical examination. The swabs were submitted to the Phoenix Police Department crime lab for analysis.

The girl was then taken to the hospital and given the morning-after pill as a precaution.

Assistant Principal Brelow told the lead investigator there were no surveillance cameras at the school. The girl told police they walked "back into the woods" and ended up in a "secret corner."

"That boy couldn't have brought her that distance without understanding her comprehension level and that makes me sick, too," said Peterson.

Det. Peter Best from the Family Investigations Bureau, Crimes Against Children's Unit was the lead investigator on the case. According to the police report, he found a location in the crime scene – just outside school property on the northeast corner of the practice football field -- where the dirt was disturbed as if a body had been laying there. He also found a lanyard and a feminine pad in a field adjacent to the campus.

According to the police report, a crime-scene technician used an alternative light source in an attempt to locate biological evidence at the scene. None was found.

Det. Best would conduct recorded interviews with all three special-education teachers, Shelley LeValley, Melissa Lane-Isaksson and Jennifer In-Albon.

The girl would undergo two forensic interviews with forensic interviewer Jennifer Ingalls.

Transcripts show the girl said she and an unidentified boy "humped." She later said they had sex. She said she wanted to throw up and wanted to quit, but the boy did not want her to quit.

She then stated that the boy told her she was not doing it right and he had to show her what to do. The teen said she told the boy no and said she wanted to go back to the dance but says he told her to stay and no one would know about what happened.

The girl also stated the boy told her that she was "a little better than the other girls." She stated to the forensic interviewer that the boy told her that she was "not ready" for him.

She said she was afraid to go back to school.

Having a blast!

Text messages between Shelley LeValley and Peterson would call into question LeValley's sequence of events that night.

At 9:42 p.m., Peterson sent LeValley a text message. She asked her how her daughter was doing. At 9:45 p.m., LeValley responded, "Having a blast!" She wrote she was leaving now and added that Peterson's daughter knows where to find Ms. Lane, the other special-education teacher who was chaperoning.

LeValley was supposed to leave at 9:30 p.m. Our investigation revealed LeValley's text message to Peterson contradicts what she would later tell police when she was interviewed on Oct. 14, less than three days after the dance.

During a recorded interview with police, LeValley said, "I kept thinking I saw her but it wasn't her. And I couldn't find her so it was like 9:45 at that point – I'm just going to go."

"She says she leaves at 9:45 p.m., she can't even locate my daughter but I have a text that says 'Having a blast!' at 9:45 p.m.," said Peterson. "How could you sleep at night? Because I haven't. I have not."

The case stalls

Nearly four months after the Phoenix Police Department began its investigation, Det. Best called Peterson with news for which she was ill prepared: semen was found on her daughter's underwear.

But Best told her, after several levels of review, including consulting with the Maricopa County Attorney's Office, a decision was made to close the case.

In a recording Peterson made of the call, Best is heard saying, "Unfortunately the elements that meet sexual assault are not there in this case based on [the girl's] mental ability."

Best also said the decision was partly based on statements she made during her forensic interviews.

Best explained a sexual-assault victim either has to be forced or be mentally incapable of consenting to sex. But during the interview, Peterson's daughter told police she willingly performed some acts with the boy because she was worried he'd be mad at her if she didn't.

"She said she willingly did some of this stuff with this boy," Best said.

Phoenix police would not agree to any on-camera interviews in this case, but spokesman Sgt. Trent Crump wrote in an email that it was determined that the elements of a criminal offense could not be established, and the investigation determined that the allegation of sexual assault could not be substantiated.

Crump wrote that the investigation moved forward to determine if the elements of sexual conduct with a minor existed, but said evidence presented suggested that both parties were juveniles and/or in high school, which Crump said would afford a defense to any prosecution.

He said investigators evaluated the availability and mental cognition of Peterson's daughter to provide consent or voluntarily participate in the conduct.

He also said Peterson's daughter misstated her age prior to the incident. Crump further stated:

"We will respect the rights and privacy of these individuals, in what is a very private and potentially humiliating incident which has been determined to lack criminal conduct."

The girl's cognitive ability

Her individualized education plan (IEP) provided to 12 News by her mother shows the girl is in classes with autistic students, though not autistic. Further, it shows she:

*Is often distracted in class.

*Will copy an inappropriate behavior in order to get attention.

*Needs reminders to be aware of her surroundings, as she is often unaware that she is standing in a doorway.

*Struggles to identify potentially dangerous settings or outcomes of dangerous scenarios. She stated she would get in a car with a stranger because she would be curious and maybe they were nice.

The document concludes her cognitive ability falls within the very low range.

Is she capable of consenting?

Dr. Cassia Spohn is one of the foremost experts on sexual assault. She's the foundation professor and director of the School of Criminology and Criminal Justice at Arizona State University. She has conducted studies and written about sexual assault for two decades, focusing on a prosecutor's decision to charge and police decision-making in sexual-assault cases.

"Police simply don't make arrests in the majority of sexual-assault cases," she said.

12 News provided Spohn the police report in this case for her to review.

"It sounds to me she was not able to consent, that she did not have the mental ability to understand what was happening to her and to give a voluntary and intelligent consent to the acts that occurred," she said.

Spohn went onto say it seems the school was at fault for not ensuring the safety at a school function of someone who apparently lacked the ability to consent to the acts in question.

Spohn says these are very difficult cases to prosecute and says it appears Phoenix police did their due diligence in this matter by investigating and attempting to identify the boy, but the fact that Peterson's daughter could not identify with sufficient specificity who the boy was probably tied their hands to some extent.

"The school, it doesn't appear, is taking responsibility for what happened to her," said Spohn.

Accepting responsibility?

Shelley LeValley texted fellow special-education teacher and chaperone Melissa Lane-Isaksson after she left the dance, during the search for Peterson's daughter. The text message reads, "Does that mean she's still not with her mom? Ugh, I feel responsible."

"You let this happen. I did everything like I should have for her. And I wasn't there to protect her and I'll never, ever forgive myself for that," said Peterson.

Once Phoenix police dropped the case, any attempt to find the boy who was with her daughter that night ended. DNA results have not yet come back from the Phoenix Police crime lab.

The Paradise Valley Unified School District issued a statement, which reads in part:

"Pinnacle High School Administration and staff have cooperated fully and completely with the Phoenix Police Department on its investigation and provided the police with any support requested. The Phoenix Police Department has informed us they were unable to establish the elements of a crime and the case was recently closed. Any additional questions about the case should be referred to the Phoenix Police Department.

"In closing, the Paradise Valley Unified School District followed all proper protocols related to this alleged incident and cooperated fully with the Phoenix Police Department's investigation. Out of respect for the privacy of our students and their families, we will not comment further on this case."

Transfer to another school?

On March 31, shortly after 12 News began investigating, a special meeting was called at the school with Peterson, the special-education administrator, and special-education teachers. At that meeting, the school officials made the recommendation to move Peterson's daughter to another school in the district.

In fact, her special-education teachers unanimously recommended she be moved because there are very few females in the program she is in.

At the meeting, Peterson was given a draft individualized education plan, which reads in part, "The team believes her needs would be better met due to smaller campus, smaller class sizes and she would be in a program that met her academic, socaial [sic] and functional needs."

The recommendation indicates Peterson's daughter's middle school should not have placed her in the autism program at Pinnacle High School. The middle school team indicated her functioning and academic levels were at a higher level than they are.

The plan ends by stating, "Due to her academic, functional and social abilities being very different than those in the autism program at Pinnacle, the team continues to have the same concerns about Pinnacle, and feel it's an incorrect placement."

Dr. Spohn weighed in on the recommendation, saying, "It appears that she's being punished for something that happened to her."

The district refused our request for on-camera interviews, but after we alerted them to the opinion of our expert Dr. Spohn, we received an updated statement. It reads in part:

"Our first priority is always for the safety and well being of all of our students and staff. The alleged offense occurred off campus and after the dance. We encourage you and Doctor Spohn to review the facts of this case in its entirety with the Phoenix Police Department."

To clarify, our report and Spohn's review are based on all the records supplied to us by the school district and the Phoenix Police Department. Text messages between teachers and a recorded interview with a teacher by police indicate they lost track of the girl midway through the dance.

Any attempts to find the boy the girl was with ended when police closed the case.

Prior to the airing of 12 News' broadcast report on April 23, the school psychologist called Peterson to say Pinnacle High School still has room for her daughter the next school year.