The most important question had no answer.

Why would a young man with almost no criminal history coax a girl into his home, expose his genitals to her, and grab her by the coat when she tried to leave?

"I can't answer that question," Natrona County District Judge Scott Skavdahl said Friday, as he considered the appropriate punishment for the man, 25-year-old Aaron Ridley. "Because I can't answer that question, I don't know what I can do to stop him. And that scares me."

Rejecting a plea for leniency and probation, the judge sentenced Ridley to six to 15 years in prison for indecent liberties with a minor.

"I don't know when Jekyll is going to arrive again," Skavdahl said after imposing the sentence.

Ridley, dressed entirely in black, waived goodbye to his family before deputies escorted him from the courtroom. Minutes earlier, he apologized for exposing himself to the girl inside his father's Paradise Valley area home.

"I want her to know she didn't deserve what happened to her," he said. "I worry every day about her and her family."

"What I did was horrible," he added. "It was absolutely horrible."

Police arrested Ridley at the home on Feb. 18 after the girl's mother reported a man had grabbed her daughter. The elementary school-aged girl, who did not attend the sentencing hearing, later said she had encountered Ridley as she went to her mailbox. Ridley told her he was looking for a dog and asked if he could walk with her.

They went to his house, and once inside, he exposed his genitals to her. The girl screamed and Ridley grabbed her coat as she tried to leave. She managed to run out of the house and back to her own home.

Ridley pleaded no contest in August to indecent liberties with a minor as part of a plea agreement with prosecutors, who dismissed charges of kidnapping and sexual exploitation of a child.

In court Friday, Ridley acknowledged what he had done, but said the act wasn't in his nature. He told the court he doesn't deserve forgiveness from the girl's family.

"I just desperately want them to know they don't need to be scared of me," he said.

The girl's parents attended the sentencing but did not address the court. Instead, they provided the judge with a victim impact statement.

The hearing began with District Attorney Michael Blonigen calling Ridley "every parent's worst nightmare." He said Ridley, who was free on bond for most of the legal proceedings, left the girl and her family in a prison of fear.

"What he did, judge, is absolutely reprehensible," Blonigen told Skavdahl.

Defense attorney Kerri Johnson said a doctor who evaluated her client concluded he is neither a pedophile nor a predator.

"I think he is a good, decent person who did a bad thing," she said.

Ridley, she told the court, was indeed looking for a dog on the evening of the incident. She argued he did not force the girl into the home and that he had intended to apologize when he grabbed the girl's coat.

Ridley claims he does not remember the incident. Johnson said tests after his arrest showed he had a blood alcohol concentration of 0.28 -- more than three times the legal driving limit.

Still, Ridley did not blame the booze for what happened.

"I blame myself," he said. "Alcohol was part of my everyday life."

Johnson asked Skavdahl for a suspended prison sentence for her client, with at least five years of probation and time at the Casper Re-Entry Center or other program.

The judge, however, felt probation and a suspended sentence weren't appropriate. Skavdahl said prison was necessary, in part, to deter others from committing similar crimes.

"This child will never look at an adult in the same light," he said. "This is something you see on TV and it happened in our community."

Reach crime reporter Joshua Wolfson at (307) 266-0582 or at josh.wolfson@trib.com.