Norman Wielsch, 51, of Concord, pleaded guilty in U.S. District Court in Oakland to charges including narcotics possession, distribution and sales, theft from a federally funded program, and civil rights violations including conducting illegal searches and seizures.
He had previously pleaded not guilty to the charges, and changed his plea today.
Wielsch, the former commander of the now-defunct Contra Costa Narcotics Enforcement Team, today admitted to committing a series of crimes between 2009 and 2011 that included stealing marijuana and methamphetamine seized during CNET raids and selling the drugs with the help of Antioch private investigator Christopher Butler.
He also admitted to teaming up with Butler to target prostitutes and steal cash, cellphones and other items from them under the guise of making an arrest.
In court today, Wielsch tearfully apologized to his family members and former colleagues, saying he had "tarnished the badge" he wore.
"I am so sorry to all of the police officers out there who are hard-working, honest people," he said.
Wielsch was taken into custody after today's hearing, and faces a minimum of 10 years in prison when he is sentenced on Feb. 19.