Police officers who opened fire while disrupting a robbery at a fast-food restaurant in Omaha killed a crew member with the TV show Cops as well as the suspect, who was armed with a pellet gun that they thought was a real handgun, authorities said Wednesday.

The suspect fired from the pellet gun before officers returned fire, Police Chief Todd Schmaderer said at a news conference. He said witnesses and officers thought the robbery suspect's Airsoft handgun looked and sounded real, but discovered later that it fires only plastic pellets. The suspect was struck by the officers' gunfire, but fled outside of the restaurant before collapsing.

Officers continued firing on the suspect as he exited the restaurant, and that was when the Cops crew member, 38-year-old Bryce Dion, was also struck, said Schamaderer. Dion was wearing a bullet-proof vest, but a single bullet that hit his arm "slipped into a gap in the vest" and entered his chest, Schmaderer said.

'If I'd have known that this would happen, of course, I wouldn't have done it.'- Omaha police chief, on allowing Cops to film in the city

"My concern with my officers is that they are taking this very hard," Schmaderer said. "Bryce was their friend."

Schmaderer said video captured by another crew member of the Cops TV show shows the chaotic situation in the restaurant. Police released still shots from the video showing a hooded and masked person pointing what looks like a gun at police. Schmaderer said police would not release the full video, but that it will be part of the grand jury investigation into the shooting.

The suspect was identified as 32-year-old Cortez Washington, who was on parole. Schmaderer said Washington had a lengthy criminal record, including an accessory to robbery conviction from Missouri. He started parole in August 2011 and transferred to Nebraska in September 2013. His parole was due to expire in June 2017.

Schmaderer said the incident began when one of the officers, on his way to another reported robbery, called about the robbery at the Wendy's and requested backup. The Cops crew members were with two officers who responded to that request.

When police entered the restaurant and confronted the suspect, Dion, who was the sound operator, got separated from the cameraman, Schmaderer said.

Langley Productions is based in Santa Monica, Calif.

Key executives of the company, President John Langley and Executive Producer Morgan Langley, attended the police news conference in Omaha on Wednesday.

"Bryce has been with us for seven years," said Morgan Langley, who hired Dion. "This is very hard for us."

Cops has been airing since 1989, switching networks from Fox to Spike earlier this decade.

John Langley said the crew had been filming all summer in Omaha and had only one week left in the city when the deadly shooting happened.

In 2010, a TV crew for the A&E reality show The First 48 recorded a Detroit police raid in which a seven-year-old girl was accidentally killed by an officer. That incident highlighted concerns about whether TV cameras influence police behaviour, perhaps encouraging showboating.

Schmaderer on Wednesday bristled at a reporter's question about whether his officers overreacted knowing that cameras were recording them, calling the suggestion "absolutely ridiculous."

Schmaderer said he accepted the invitation from Cops to film in Omaha in the name of transparency. But he also expressed regret at the outcome.

"Personally, I will live with this forever," Schmaderer said. "If I'd have known that this would happen, of course, I wouldn't have done it."