Contra Costa County District Attorney Diana Becton announced Thursday that prosecutors will move to dismiss one felony and two misdemeanor cases potentially tainted by the testimony of a former Antioch detective who was fired in 2017 for leaking information to known criminals, among other misconduct.
Former Antioch Detective Santiago Castillo’s misconduct came to light through records obtained by a coalition of news organizations, including KQED, called the California Reporting Project, that is collecting officer misconduct and serious use-of-force information throughout the state under a new police transparency law, Senate Bill 1421.
The records show Castillo was suspected of sharing confidential information with suspected criminals as far back as 2010. When internal affairs investigators confronted Castillo, they found his explanation, that he sometimes told informants police were watching them “to scare them,” was not credible. Investigators also found Castillo had submitted overtime that he didn’t work and had mishandled evidence.
After the district attorney’s office learned of Castillo’s misconduct, its conviction integrity unit undertook a review of “numerous” cases in which the veteran officer had testified, checking if his now-questionable credibility undermined those prosecutions. The review included an unknown number of prosecutions for murder and other serious charges.
“At the end of that review, I determined that there were three cases for which we could not be certain that the interests of justice were served by the outcome, and out of an abundance of caution, we’re going to move to dismiss those cases,” Deputy District Attorney Brian Feinberg said.
