DALLAS (CBS11) – Three witnesses testifying in Dallas County criminal court Tuesday, recounted the moments they saw former Farmers Branch Police Officer Ken Johnson open fire on two teenagers.

Ken Johnson (credit: Addison Police Department)

“I thought I was witnessing a murder, “ Michael Stanislaus, an Addison resident testified.

Stanislaus was riding in a car with two friends on March 13, 2016 when they witnessed the shooting involving the former police officer.

“He charged the car with his gun drawn, and started unloading into the driver side,” Stanislaus said.

Johnson is charged with murder and aggravated assault with a deadly weapon.

He resigned from Farmers Branch PD after shooting and killing 16 year old Jose Cruz, and injuring Eric Rodriguez, who is 18 now.

Rodriguez testified that he and Cruz broke into Johnson’s SUV, stealing the third row seats.

Prosecutors contend Johnson saw them, chased them, then forced the teenagers’ car off the road. Witness Andrea Houston said she saw Johnson, who was not in police uniform, quickly walk toward the drivers side of the teen’s car and started shooting.

The investigator of the shooting also testified Tuesday.

Former Addison Police Detective Eric Aguilar told the jury he saw no signs the teens had a weapon, and the fatal victim Cruz was still latched in the driver’s seat with his seat belt on. Aguilar said Johnson turned his back on the occupants in the car, and didn’t inform arriving police officers of any threat.

Aguilar said Johnson didn’t follow standard officer protection, if he felt a threat.

The case resumes Wednesday.