SAN ANTONIO -- A San Antonio police officer who arrested an off-duty officer for alleged drunken driving told jurors Thursday he made a mistake when he turned off his patrol car video camera shortly after he pulled over the officer.

Officer Peter Knutsen's testimony came during the second day in the trial of Officer Israel Castro.

Knutsen (pictured, left) reportedly clocked Castro speeding at 103 mph when he stopped him in February 2002.

The arresting officer told jurors even though he turned off the patrol car dash camera, which films sobriety tests, Knutsen said there was no doubt that Castro was intoxicated.

"I based my opinion that this defendant was intoxicated by the totality," Knutsen said. "All these factors. Not one (in) particular, but the overwhelming."

Castro's attorney said without the sobriety test video, jurors can't form an opinion on how his client performed on the sobriety test.

Castro (pictured, right) did register a 0.16 blood-alcohol level, twice the legal limit in Texas, on a breathalyzer test.

He is scheduled to testify in his own defense Thursday afternoon.

If Castro is found guilty, he may be relieved of his duties on the police force.