Rodney Corsiglia, 51, was driving on a suspended license and over the speed limit on Sneath Lane in San Bruno on July 28, 2012, when he suffered a seizure and plowed into the back of a car stopped at a red light, District Attorney Steve Wagstaffe said.
The crash instantly killed two of the passengers in the rear-ended car and injured two victims in a third car.
The victims who died were fathers of a total of five children. Corsiglia knew he had a seizure disorder and was taking medication for it. Prosecutors said the seizures caused him to be involved in seven car crashes between 2002 and 2011.
A 14-day jury trial was held in San Mateo County Superior Court. The jury deliberated for five-and-a-half hours and returned guilty verdicts on all counts.
Corsiglia remains in custody on no-bail status and is scheduled for sentencing July 30.