A former deputy constable said things were happening so fast he had to make split-second decisions and one of those was shooting a man he thought was armed.

Using toy cars, former deputy constable Mario Ramos demonstrated for the jury the events that led up to him shooting Juan Ortegon.

He said the night of Aug. 16, 2008, he was trying to stop Ortegon for a simple traffic stop, but he said Ortegon fled.

Ramos said he had been hit by Ortegon twice with his car, and in one Ortegon tried to run over him as he stood outside the car.

Assistant District Attorney Kyle Lasley asked, "Why couldn't you just call for help?"

"It was split seconds," said Ramos.

Ramos said his police radio had fallen to the floor one of the times he was hit and he couldn't reach for it. He said he finally was able to grab the radio as he followed behind Ortegon the wrong way down Montwood Drive.

A recording of his call to dispatch was played in court Wednesday. In the call, Ramos told dispatch he was in pursuit, and then yelled out, "Shots fired."

Ramos told the jury Ortegon came to a stop. He said Ortegon jumped out and started running. Ramos said he followed.

Ortegon was caught, according to Ramos, but as Ortegon was being cuffed, Ramos said he took off again.

"He got me in a headlock and saw him reaching for something," said Ramos. "I feared for my life and that's when I shot him... I didn't know why he was reaching down his pants."

Ramos was then questioned what happened after the shooting.

"When I patted him down, I didn't find any weapons," said Ramos.

Ramos is facing charges of aggravated assault with a deadly weapon for shooting an unarmed man.

The defense tried to discredit Ortegon by questioning two El Paso police officers who testified they saw Ortegon walk into a store in December 2010.

They said Ortegon didn't have a limp or walk with a cane, something he's been doing during this trial. He said he walks that way because of the shooting.

The trial continues Thursday in the 120th district court.

Ramos was fired as a deputy constable after being charged with sexual assault in a separate case. Ramos has not gone on trial for those charges.

Read more in blog, "In the Courtroom"