WATCH: Surveillance video released after grand jury declines to indict cops in Walmart shooting

A grand jury declined to indict two police officers involved in the fatal shooting of a black man carrying a toy gun at an Ohio Walmart store.

One of the officers shot 22-year-old John Crawford at the store Aug. 5 after a 911 caller reported he was pointing what appeared to be an assault rifle at other shoppers at the Beavercreek retailer.

Grand jurors heard evidence from 18 witnesses Wednesday in the special hearing convened by Ohio Attorney General Mike DeWine, who refused to release surveillance video from the incident prior to the hearing.

The U.S. Department of Justice announced Wednesday afternoon that it would launch an investigation into the fatal shooting.

Police said Crawford refused to drop the air rifle, but his father and the family’s attorney said the video, which they were permitted to view before the grand jury, directly contradicted the official story.

They said the video showed Crawford talking on a cell phone while leaning on the toy rifle like a cane when officers approached from behind.

The family’s attorney said it did not appear that Crawford ever heard their commands to drop the toy weapon before he was “shot on sight.”

Assistant Hamilton County, Ohio, Prosecutor Mark Piepmeier presented the case as a special prosecutor.

He showed portions of the video during a news conference announcing the grand jury decision Wednesday, with audio from the 911 call synchronized with Crawford's actions inside the store.

Crawford never waved the toy gun or appeared to point the weapon at anyone, but he did walk briefly with the air rifle resting on his shoulder.

He was shot almost immediately after officers spotted him at the end of an aisle, the video shows.

Piepmeier said the 911 caller was "trying to be a good citizen" by reporting the perceived threat, and the prosecutor said Crawford likely became distracted by his own cell phone call and began carrying the gun carelessly.

Dispatchers told officers to expect a man pointing a rifle in a threatening manner, the prosecutor said.

He said both Sgt. David Darkow and Officer Sean Williams underwent department-mandated training on active shooters in July, saying the training required them to immediately “neutralize the threat” in such cases.

The special prosecutor said grand jurors were tasked with determining officers acted reasonably against a perceived threat.

"(Crawford) did not commit a crime that day, he didn't do anything wrong, but at the same time the police officers have be judged on everything they have," Piepmeier said. "All I have to say about the situation is that it's a tragedy."

He expressed sympathy for Crawford's family, relatives of a woman who suffered a medical emergency after witnessing the shooting and died, and both officers.

"They took the life of someone that didn't need to die, that's all we have to say about this case," Piepmeier said.

Watch surveillance video of events leading up to the shooting posted online by WDTN-TV:

Watch video from the shooting itself posted online by WHIO-TV: