DENVER - He claimed he was insane, but jurors decided he was not, and they found Bret Lee Luckett Thompson guilty of kidnapping and sexually assaulting an 8-year old girl.

That verdict was returned after less than two hours of deliberation Monday morning.

Defense attorneys admitted in opening statements that Thompson kidnapped and sexually assaulted the girl in June of 2011, but he pleaded not guilty by reason of insanity.

The jury obviously didn't believe Thompson.

"We want to thank the jury, this was a hard case to hear and deliberate on. And our little victim, we'd like to thank her. Her strength was well beyond her age," said Deputy District Attorney Allison Rocker.

Thompson will be sentenced in May.

The victim, now 10, testified last Tuesday.

She said she was playing with a friend in an alley when a man pulled up in a van and asked for help putting a box in the trash.

The girl, who is not being named, said the man lifted her up so she could place the box in the Dumpster, then put her in his van and drove off.

The girl said she asked him to "pinky promise" he wouldn't hurt her.

She said the man drove her to a garage and took off her pants.

"He took out his man part and put it in on my private part," the girl testified, and then she started crying.

She said after the assault, the man told her to put her clothes back on.

He then drove her back to west Denver and dropped her off at a gas station.

“I went inside and said to help me because I just got kidnapped,” she said.

The clerk called the girl’s mom, then called police.

"She went through an awful thing and was able to stand up to the person who did it to her," Rocker said after the jury delivered its verdict.

Thompson's defense team says Thompson suffers from Dissociative Identity Disorder.

“It was formerly known as Multiple Personality Disorder,” according to defense attorney Natalie Frei.

“He was moody and depressed and continued to have fits of rage,” Frei said of Thompson in the past few years. “He spent a lot of time in the basement and talked of suicide.”

Thompson's Foster Mom, Sylvia Luckett, declined comment today.  But Luckett's brother, Robert Pagel, told 7NEWS that Thompson "basically threw his life away."

Pagel said Thompson will probably spend the rest of his life in prison.

"Our main concern," Pagel said, "is for the young girl.  We hope she can go on with her life and will be O.K."