Matthew Valdez is charged with criminally negligent homicide, but his attorney said the other driver involved is the one at-fault because he was intoxicated.
The crash happened in late November around 3:30 p.m.
Walter Cooper, 71, was at the intersection of Darien and Ley Road in northeast Houston.
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"Walter Cooper was stopped at the stop sign at Darien Street approaching Ley Road and when he looked to his left, he saw that Matthew Valdez was at least a football field away before he entered into the intersection," said Lynn Nguyen, the Chief of Vehicular Crimes for the Harris County District Attorney's Office.
Surveillance video from that day shows Cooper's black car at the stop sign. Then, a police car drives by. Moments later, a second police car passes, which was the one driven by Valdez, and crashes into Cooper's car.
WATCH: The video below from the scene shows damage from the crash
"We're deeply saddened and very disappointed in the grand jury's decision to indict this case," said Valdez's attorney, Brent Mayr. "This was a tragic accident, but there was no crime committed here. Nothing officer Valdez did rose to the level of criminal negligence."
Court records said Cooper's blood alcohol was three times the legal limit.
"Every person in this county knows the dangers of drunk drivers," said Mayr. "We know the Harris County District Attorney's Office prosecutes people for intoxicated driving. He had no business being on the road in the first place, and just because he stopped at the stop sign doesn't mean he wasn't at-fault."
However, prosecutors disagree.
They said Valdez was driving 90 miles an hour in a 35 mile-per-hour zone and did not use emergency lights or sirens.
"The surveillance video clearly shows that Walter Cooper was at a complete stop for a complete full two seconds, so he actually didn't do anything that a sober person would also not have done," said Nguyen.
Mayr said Valdez was suspended by HPD and later resigned. He then went to work for the Harris County Precinct 3 Constable's Office. He resigned from that position on Tuesday. His attorney said he hopes to return to law enforcement one day.
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