Sister of man shot, killed by undercover cop speaks out

A sister fights back tears - as she remembers her little brother.

"He was going to be 30 next month. Now, I won't be able to see him turn 30. It breaks my heart because he was my little brother. It hurts so much," Ada Martinez said. 

Martinez said she relived the warm January day she lost her brother, Josue Diaz, as she heard the just released 911 calls and police radio traffic.

Related: Man shot, killed by CMPD officer during apparent road rage incident identified

"I didn't finish listening to them. I just couldn't," she said. 

In one of the tapes, the caller describes the scene.

For context, Josue Diaz and a passenger were in the truck.

The undercover officer was in the brown SUV.

911 caller, "I need police bad. I've got a guy in a brown SUV on Albemarle Road shooting five or six times at another guy in a truck in front of him. Now, he's walking up to the windshield and holding a pistol on the guy."

Police said an undercover officer shot and killed Josue Diaz on Albemarle Road.

They said Diaz sideswiped the undercover cop car, drove off, and then got out of his truck to approach the undercover officer with a gun.

The passenger inside the truck said Diaz did not have a gun when he got out of the vehicle.

"I didn't hear anybody saying, he started shooting so he shot back. Nothing like that," said Martinez.

This is a clip from the undercover officer over police radio traffic.

Radio traffic: "Shots fired, shots fired, shots fired. One down. I need medic. It doesn't look good."

Police said they found a bullet hole in the undercover officer's car which matches the gun they say belonged to Diaz.

In addition to that, a law enforcement source told FOX 46 Charlotte that Diaz was a member of the Sur 13 gang.

We asked,"As his sister, can you say whether or not he was?" "Not that I know of. I know all of his friends and I never saw them doing any activities like that. Just because he had 13 on him doesn't mean he was a gang member."

In the end, Diaz’s family said, "We just want answers. We want to know what really happened. Why the undercover cop did what he did and shot him that many times. We just want closure so we can move on."