SPRINGFIELD, Mo. -- The family of a man who was shot and killed by a Springfield police officer plans to ask the federal government to investigate the case.

Greene County prosecutors announced last week no criminal charges would be filed against former officer Andrew Bath in the death of Michael Ireland, 31, who was shot Feb. 17 after he ran from officers investigating suspicious activity in north Springfield.

Bath said he shot Ireland when he reached toward his waistband because the officer thought Ireland might be going for a weapon. Ireland was unarmed.

Prosecutor Dan Patterson ruled last week the shooting was justified, prompting a lawyer for Ireland's father to draft a letter to the Department of Justice asking federal investigators to look at the case.

"I didn't really think it would turn out that way," said Steve Ireland, Michael's father. "I want the officer to be held accountable."

Attorney Joshua Roberts said the family also will file a wrongful-death lawsuit if no financial settlement is reached.

"In the state criminal court system, the opportunity to get justice has been foreclosed upon," Roberts said. "So we are left with trying to get justice in the civil arena."

Patterson said Bath chased Ireland to a gate, where the two men came face to face. He said Bath twice used a Taser on Ireland before the shooting.

Roberts said the family wonders why Bath didn't continue using his Taser or why he didn't open the gate and handcuff Ireland.

Springfield chief Paul Williams declined to release results of an internal police investigation or discuss the case, citing the pending litigation, The News-Leader said.

Ireland's parents, Steve and Pennie Ireland, said the family misses him.

"It's hard, and I don't think it will be easy ever," Pennie Ireland said. "We've missed some key moments recently."

Ireland's father said Ireland dropped out of high school in ninth grade because of difficulty caused by ADHD. He served time in prison for tampering with a motor vehicle, but his family said he was never charged with any violent crimes.

Bath resigned from the Police Department. When reached at a furniture store where he works in Alabama, he declined to comment on the case, citing his lawyer's instruction.