Attorneys and advocates are questioning why an 18-year-old East Texan with profound mental disabilities was sentenced to 100 years in prison in a child sex abuse case.

They say the case of Aaron Hart was mishandled from start to finish and raises questions over how to deal with the mentally disabled when they encounter the criminal justice system.

After a neighbor found Hart fondling her 6-year-old stepson in September, the East Texas teenager pleaded guilty to five counts, The Dallas Morning News reported Wednesday.

Hart has an IQ of 47 and was diagnosed as mentally disabled as a child. He never learned to read or write and speaks unsteadily. Despite being a target of bullies, he was courteous, well-behaved and earned money by doing chores for neighbors, supporters said. His parents say he'd never acted out sexually.

"He couldn't understand the seriousness of what he did," said his father, Robert Hart. "I never dreamed they would think about sending him to prison. When they said 100 years — it was terror, pure terror, to me."

Aaron Hart pleaded guilty to charges including aggravated sexual assault and indecency by contact, and his case went to a jury for punishment. Jurors had the option of probation, former attorney Ben Massar told The Associated Press on Wednesday.

But during sentencing, Lamar County Judge Eric Clifford decided to stack the sentences against Hart after jurors settled on two five-year terms and three 30-year terms in February. At the time, Hart had already been on probation on a misdemeanor theft charge and had faced a misdemeanor charge of criminal mischief, Massar said.

Clifford said neither he nor jurors liked the idea of prison for Hart but felt there wasn't another option.

"In the state of Texas, there isn't a whole lot you can do with somebody like him," he said.

Jurors say they sent the judge notes during their deliberations asking about alternatives to prison but didn't get a clear answer. They believed the judge would order concurrent sentences, jurors said.

Texas Tech University law professor Daniel Benson called Hart's punishment absurd. Repeat child molesters and rapists have routinely received lighter sentences.

"That's not helpful to society or the offender," said Benson, an author of textbooks on criminal offenders with mental illness.

District Attorney Gary Young said he sympathized with Hart's situation but stands by his decision to prosecute Hart on five counts. Prosecutors commonly pursue several charges for the single incident to see which the jury will support.

"I hope people will remember he committed a violent sexual crime against a little boy," he said.

Advocates say counseling, probation or placement in a group home would have been more appropriate. But Young said a diversion program was not an option since the law doesn't allow that for serious felonies.

The prosecutor also points out a psychologist found Hart competent to stand trial, showing the teenager "knew right from wrong."

"Mr. Hart is not severely mentally retarded to the point he doesn't understand what's taking place around him," said Allan Hubbard, a victim's advocate for the district attorney.

But David Pearson, Hart's appellate attorney, said the court-appointed doctor did the bare minimum to assess competency and ran tests geared for mental illness, not mental retardation.

Pearson also says Hart's court-appointed defense attorney, Massar, didn't do enough. The lawyer failed to present evidence and expert witnesses to testify about Hart's mental capacity and didn't ask for special accommodations, such as a liaison to explain to Hart what was happening in court, Pearson said.

Massar countered the assertion.

"The jury had a real sense of Aaron's mental state," he said. "They knew exactly what his mental capability was."

In denying Hart's request for a new trial, the judge found he had been an effective attorney, Massar said.

"They're attacking the attorney because there's no other basis to attack the case now," he said.

For now, Hart is serving his time at a special Texas prison unit that houses nearly 1,000 inmate with mental disabilities.

"He keeps saying he'll be out soon, he'll be home with us, that maybe he'll get probation," said Hart's father, Robert. "It's the hardest thing I've ever had to hear."