Killings By Police Oklahoma

In this screen shot from April 2, 2015, video provided by the Tulsa County Sheriff's Office, police restrain 44-year-old Eric Harris after he was chased down and tackled by a Tulsa County deputy, and then shot by a reserve sheriff's deputy while in custody.

(Tulsa County Sheriff's Office via AP)

A 73-year-old reserve deputy in Tulsa, Okla., is under investigation after he shot and killed a suspect earlier this month when he mistook his handgun for a Taser, authorities say.

But the incident also is gaining national attention because other deputies can be heard on video berating the suspect, Eric Courtney Harris, 44, after he had been shot by Tulsa County Reserve Deputy Robert Bates.

The shooting occurred on April 2 in Tulsa during an undercover sting operation. Days earlier, Harris, an accused felon, had sold methamphetamine to an undercover officer, CNN reports. During the sting, he tried to sell an illegal handgun to an undercover officer in a vehicle.

As police pulled up on the scene, Harris jumped out of the car and ran. An officer caught up to Harris and Bates arrived moments later. As officers try to restrain Harris, Bates can be heard yelling "Taser" before a shot rings out. Bates then immediately apologizes.

"Oh! I shot him! I'm sorry!" Bates can be heard saying on video.

"Oh, God. Oh, he shot me," Harris yelled.

Harris then complains that he's losing his breath, at which point a deputy can be heard saying "F--- your breath."

Harris was taken to a hospital, where he died about an hour after the shooting, reports the Los Angeles Times.

CNN reports that Tulsa Police Sgt. Jim Clark, who has been brought in to review the case, said Bates "inadvertently" shot Harris and described Bates' actions as "slip and capture":

Quoting Bill Lewinski, executive director of the Force Science Institute, Clark further explained: "These are mistakes that are made when you think you are doing one thing but you actually are doing another, and the result often is directly opposite of what you intended. In effect, your intended behavior slips off the path that you want it to go because it is captured by a stronger response and sent to a different direction."

Clark also defended the deputy heard berating Harris, saying that it's likely he didn't hear the gunshot because he was so focused on restraining Harris. He said the deputy thought Harris was out of breath from running.

"It is my opinion, after reviewing all the facts and circumstances of this case, [the state's excusable homicide statute] was applicable in this incident," Clark tells the L.A. Times. "Reserve Deputy Bates did not commit a crime. Reserve Deputy Bates was a victim, a true victim, of 'slips and capture.' There's no other determination I could come to."

The case has been referred to the Tulsa County District Attorney's Office, which will decide whether to file charges, the Times reports.

Harris family said in a statement it doesn't think it's "reasonable" to believe Bates mistook a handgun for a Taser.

"We do not believe it is reasonable for a 73-year-old insurance executive to be involved in a dangerous undercover sting operation," the statement says. "... We do not believe it is reasonable - or responsible - for [the sheriff's office] to accept gifts from a wealthy citizen who wants to be [a] 'pay to play' cop."