Gallo's blood-alcohol level was measured at 0.19 percent two hours after the collision, but prosecutors say it was closer to 0.22 percent, nearly three times the legal limit, at the time of the crash.
Gallo's minivan was going 66 mph in a 35-mph zone eastbound on Orangethorpe Avenue when it broadsided the Mitsubishi Eclipse carrying the four victims on Lemon Street about 12:20 a.m., according to the testimony of Wes Vandiver, an investigator with the Orange County District Attorney's Office.
Prosecutors said they took the unusual step of charging Gallo with second-degree murder, and not the lesser charge of manslaughter, in part because he had a prior drunken-driving conviction and because he was driving on a suspended license.
Gallo faces a maximum sentence of 54 years and eight months to life in state prison if convicted of all counts.
The 22-year-old Adenhart died just hours after pitching six scoreless innings in his 2009 season debut with the Los Angeles Angels.
