SIERRA VISTA — An argument over a drug debt left two people dead Tuesday evening after they were shot several times by a man who claims he killed them in self-defense, police said.

At least eight people watched the skirmish between shooter Devon Neff and the deceased — identified as 25-year-old Landan Klein and 25-year-old Honeylynne Garcia— unravel in the parking lot of Filiberto’s on East Fry Boulevard, said Sierra Vista Police detective Paul Youman.

A surveillance video from the popular eatery shows Neff firing at Klein as the latter walks away from Neff’s car. Neff then gets out of his automobile and shoots Garcia several times after she opened the passenger-side door of Klein’s vehicle, police said.

A police spokesman said Thursday that Neff, 21, owed Klein money for drugs.

The two deaths become the second and third homicides in the city in less than a month. On June 21, Luis Armenta Rivas was shot to death on a residential street in front of four or five people, police said. In that instance, the shooter — who has not been arrested and whose name has not been released — also claimed self-defense, investigators said.

This shooting occurred at 7 p.m. Tuesday, police said. The Filiberto’s video, obtained by detectives, shows the driver of a Chrysler 300 pull up next to a Dodge Challenger in the parking lot of the restaurant.

Klein emerged from the Chrysler and walked over to the driver-side window of the Challenger where Neff was sitting, police said. The two men had words and Klein punched Neff several times. As Klein walked away, police said Neff pulled out a gun and shot him, prompting Klein to run. Neff then got out of his Challenger and walked to the rear of Klein’s Chrysler, detectives said. At that point, Garcia, who was sitting in the front passenger seat, opened the door. Investigators said Neff shot at her. He then crouched behind the Challenger, adjusted his firearm, stood up and fired at Garcia three or four times.

Neff then drove off. About 30 minutes later, Neff called emergency dispatch and told a dispatcher that he was the shooter and that the incident was in self-defense, Youman said.

Police obtained a search warrant and took drug-related evidence from Neff’s apartment at Sierra Charles Apartments off Seventh Street. Neff and his girlfriend were taken into custody, but she was later released, Youman said.

On Wednesday, investigators also searched the residence Klein and Garcia shared in Sierra Vista and found drug-related evidence linking them to Neff, Youman said. Garcia’s siblings, Roger Garcia and D.J. Garcia of Salton, California, were at Klein’s house and were arrested, police said. The brothers were charged with possession of marijuana for sale, possession of dangerous drugs for sale and four counts of misconduct with weapons.

Neff, booked into Cochise County Jail with a gash across his nose, has been charged with two counts of second-degree murder.

The case remains under investigation and anyone with information is asked to call Youman, 520-452-7500.