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Here's a closer look at the tape and an interview with the man it exonerated.
In the LAPD's Rampart Division, the police department has been accused of multiple cases of police corruption years ago; and for that reason, was slapped with a federal consent decree. Now there is a sense of déjà vu with the arrest and the exoneration of a young man who was taken into custody, caught on video.
"Before I knew it, they had taken me to their squad car and I was heading down to the station," said defendant Guillermo Alarcon.
Guillermo Alarcon was arrested in the carport of his apartment building on drug charges and put on trial. He claimed officers set him up.
"Of course because they're here to protect us, everybody assumes that they tell the truth at all times," said Alarcon.
But Alarcon's mother had installed four cameras and recorded video. It had been Alarcon's secret defense weapon for nearly a year as he prepared for a confrontation in court.
The two Rampart officers testified that they saw Alarcon drop something, and that they found a full box of drugs nearly at his feet.
Alarcon's public defender, Victor Acevedo, pointed out 30 minutes of inconsistencies and a disturbing piece of audio. An officer comes up with drugs, then there's what appears to be an instruction to the others to embellish their report on the incident.
One of the officers can be heard on tape saying, "Be creative in your write ... oh yeah, don't worry,"
"One of the officers turns around and just blatantly tells the other officers, 'Hey, be creative in your writing,'" said Victor Acevedo, Alarcon's public defender. "And then, to top that off, you have other officers actually responding, 'Hey, don't worry, we've done this before.'"
The judge viewed the tape, dismissed the case and went one step further.
"The judge made a finding that Mr. Alarcon Jr. is actually factually innocent of these charges," said Acevedo.
The prosecutor was taken by surprise. When there's evidence like this, the case is dismissed before it gets to trial. But the public defender wanted to be sure the officers were held accountable.
"The sad thing is that we have done this in other occasions," said Acevedo. "We've turned these things over to the prosecuting agency and nothing happens to the officers."
Acevedo thinks now about others the officers had arrested who had no video.
"They obviously said on the tape they did it to someone else, and somebody's in jail right now for what they've done," said Alarcon.
Three officers are currently on paid home leave. A fourth officer is now with another police department. Tuesday, Police Chief William Bratton pledged a full investigation.