The family of an Ohio man shot and killed by police in a Dayton-area Wal-Mart in August is suing police and the store. Relatives announced their decision to sue at a news conference Tuesday.

Their lawsuit targets Beavercreek, Ohio, Police Officer Sean Williams, who fatally shot 22-year-old John Crawford on Aug 5; Williams's partner, Sgt. David Darkow; Police Chief Dennis Evers; and the Wal-Mart Corp., which owns the Wal-Mart store, the Dayton Daily News reports.

"All we want is justice for John Crawford," said Michael Wright, an attorney for the family. "John Crawford broke no law. John Crawford threatened no one. Johns Crawford was shopping and talking on his cell phone. John Crawford did nothing wrong."

Police reported to the Wal-Mart after a 9-1-1 caller said Crawford was waving what appeared to be a rifle. They said he did not obey commands to put down the object, which turned out to be an air rifle his family said he'd taken off a shelf. Officers ultimately fired and killed Crawford.

Williams and Darkow were exonerated of any wrongdoing in the incident when a Greene County grand jury declined to indict them in September, Dayton NBC affiliate WDTN recalled. The shooting drew national attention amid controversy surrounding a number of confrontations beltween black men and police, most notably the death of Michael Brown in Ferguson, Missouri.

The Crawfords' lawsuit alleges that Wal-Mart and the Beavercreek Police Department were negligent in the incident, and the family said store employees were aware the man was in the store with the gun well before police arrived.

Attorneys said a video shows it took officers less than four seconds to open fire. The family is seeking restitution of at least $75,000, though that figure could change.

"This is just the beginning, as far as I'm concerned," said John Crawford Jr., the victim's father. "I'm still pursuing justice, because -- to me -- that is justice: You have to be held accountable."