On Tuesday, Stanford Graduate School of Business student Zachary Katz, 24, pleaded not guilty to three felony charges in connection with a fatal head-on collision on U.S. Highway 101 in early October, according to the San Mateo County District Attorney’s Office.

On Oct. 5, the crash killed 62-year-old Pedro Juan Soldevilla of Puerto Rico, said Chief Deputy District Attorney Karen Guidotti. Katz is charged with one count of vehicular manslaughter and two counts of felony drunken driving causing great bodily injury.

Katz’s blood alcohol content was around .15 when the crash occurred, according to the California Highway Patrol.