A former state trooper was sentenced Thursday to 90 days in jail for shooting to death an unarmed, mentally disabled man he mistook for a fugitive.

Larry Norman pleaded guilty in May to misdemeanor negligent homicide and admitted he mistakenly shot Joseph Erin Hamley, 21, on March 7, 2006, as Norman lay on the ground.

Norman, who could have received up to a year, was ordered to jail immediately, but will be freed for 10 days beginning Friday to get his affairs in order. He also must serve a year of probation and 30 days of community service at a school for disabled people and was fined $1,000.

Norman and other officers mistook Hamley for Adam Lee Leadford, an escaped inmate from Michigan.

Norman was ordered to direct traffic but instead intervened and approached Hamley. Capt. Les Brunns said that by doing so, Norman instigated the incident.

"I made a mistake. Erin Hamley didn't deserve to die. There's nothing I can do to bring him back," Norman said.

Hamley ignored commands to keep his hands out of his pockets, something his mother described as a nervous habit. Hamley asked, "Why did you shoot me?" after he was wounded.

Hamley's mother said after the sentencing that the family was satisfied with the sentence.

"We feel that justice was served and that the Constitution was upheld," Mary Hamley said. "I feel that justice was done for Erin."

The state police review board concluded that Norman and another state trooper "acted in good faith, based upon information known," but recommended additional training.

State Police Director Col. Winfred Phillips pledged to step up training and otherwise "do everything possible to prevent this from ever happening again."

State police granted Norman medical retirement last year due to what his attorney called an "enormous psychological overlay" from the shooting.

Leadford, 18, had escaped two days earlier from a Michigan prison and was believed to be in the area. He was captured the evening of Hamley's death after being shot by police in a Wal-Mart parking lot. He has since been convicted and is serving time in an Arkansas prison.