FARGO (AP) - Ryan Cheshire lost his father in a shootout and his brother in a traffic crash. The losses helped shape his journey back to North Dakota, and later to Minnesota as a prosecutor, he says.

"I lost half my family by the time I was 16," said Cheshire, 30, now an assistant prosecutor in Minnesota's Otter Tail County. "I looked at them as reasons to go on and use that as motivation to do something positive."

Cheshire's father, Robert, a U.S. marshal, was killed Feb. 13, 1983, when he and other officers tried to arrest Gordon Kahl, an anti-government protester, near Medina. Ryan was 6 years old at the time.

The Cheshire family moved to Washington state when Ryan was in the fifth grade.

His younger brother by one year, Jeremy, was killed at age 15 in a crash after a high school football game that was linked to a driver who had been drinking.

Ryan Cheshire said he began feeling sorry for himself until after the funeral, but he found strength.

"In a lot of ways, it helped me," he said. "It gave me a new motivation to go forward and to help to do what's right."

He enrolled at Central Washington University, planning a career as a federal law enforcement officer. By the time he graduated, Cheshire said, he had decided to become a prosecutor.

"The change in college was realizing I could do more as a prosecutor," Cheshire said. "That's not taking anything away from law enforcement. I found it to be my passion, my calling."

Dave Peterson, an assistant U.S. attorney in Bismarck, and his wife, Diane, are close friends of the Cheshire family. Peterson suggested the University of North Dakota law school.

Ryan Cheshire returned to North Dakota, where he met his wife. Eventually, both received judicial clerkships in Otter Tail County, and Cheshire joined the prosecutor's office in March 2005.

Otter Tail County Attorney David Hauser said Cheshire, who handles many of the county's drunken driving prosecutions, has done a good job.

"We're very happy with him, and he's a good prosecutor," Hauser said.

Cheshire said he recalls little about his father but has talked to many people about him.

"From what I've heard and been told, he was a good father," Cheshire said. "I've learned more about the incident as I got older. I know he gave his all for his country."

He recalls shaking President Ronald Reagan's hand during a trip to Washington, D.C. He has traveled to Medina to see where the confrontation with Kahl, who fled the state and later died in another shootout with officers in Arkansas, took place.

Cheshire said he granted a television interview for a documentary about how the shootout affected family members, but he never watched it.

"Part of that (shootout) in North Dakota never seems to be finished," Cheshire said. "There are some people who viewed my dad as a federal law enforcement official. To me, he was my dad."

Peterson sees strong similarities between father and son.

"He's seen a lot of adversity in his life," Peterson said of Ryan Cheshire. "I've seen him develop from 4 or 5 to a fine young man with a fine family and a good future in front of him. He's doing his life's love now."