Based on the findings of the district attorney's investigation, the detective, Kurt Rodenspiel, will not be charged with a crime, the office announced Wednesday.
The shooting occurred the morning of Aug. 13 as police were serving a search warrant at the Newbridge Avenue home of Hector Ramirez Jr., 25, an alleged Norteno gang member who was suspected of selling methamphetamine.
Ramirez had recently been released from prison on parole for a violent felony, prompting the officers to label the search warrant "high-risk," District Attorney James Fox said in a summary of the investigation addressed to San Mateo Police Chief Susan Manheimer.
Officers arrived at Ramirez's home at 1448 Newbridge Ave. in San Mateo early on the morning of Aug. 13 and began to conduct surveillance. At about 10 a.m., a gray Mitsubishi Eclipse parked in front the home, Fox wrote.
The driver, later identified as 24-year-old Joseph Ortega, exited the car and walked toward Ramirez's house but then returned to his car and climbed back into the driver's seat. A short time later, Ramirez came out of the house and got into the car, Fox said.
One police car then pulled up and stopped just behind the Mitsubishi, and a second police car parked in front of it, blocking it in.
As officers exited the car in front, Ortega stepped on the accelerator and rammed the Mitsubishi into it, Fox said.
Rodenspiel, who had been in the police car parked behind the Mitsubishi, started to walk toward the Mitsubishi on the passenger side, carrying an MP5 gun with the safety off.
As he approached the Mitsubishi, Rodenspiel stumbled on the curb and lost his balance, causing his weapon to discharge, Fox said.
Because the gun was not in a position to fire and was at Rosenspiel's waist, the bullet entered the trunk area of the Mitsubishi, penetrated the seats and struck Ortega, Fox said.
Emergency medical responders were summoned and Ortega was airlifted to Stanford Hospital, where he wore a breathing tube for 24 hours.
As soon as the breathing tube was removed, allowing Ortega to speak again, he uttered an expletive followed by, "Pigs shot me," according to Fox.
The district attorney's office has determined the shooting was accidental based on the angle the bullet entered the Mitsubishi and the observation that a sergeant and officer were in front of the Mitsubishi and therefore in a position of risk if a shot were fired from where Rodenspiel stood, Fox said.
Oretga has been charged in San Mateo County Superior Court with assault with a deadly weapon on a peace officer and battery on a peace officer, both felonies, Assistant District Attorney Karen Guidotti said.
He has not yet entered a plea, and faces up to five years in prison if convicted.