Lucas McFadden, the 23-year-old Petaluma resident with West Marin roots who was charged with gross vehicular manslaughter this winter, pled guilty in Marin Superior Court last week. According to his plea deal, Mr. McFadden faces six years in state prison and will be forgiven of two intoxicated driving counts, Deputy District Attorney Emily Cordell said. On Jan. 29, Mr. McFadden was driving 18-year-old Ricardo De Santiago south from the Marshall Store, where they both worked, when he drifted into oncoming traffic on Highway 1 and crashed headlong into a dump truck. Mr. DeSantiago died on the scene and Mr. McFadden suffered a broken pelvis and shoulder, a rib fracture and head injuries. He remains in custody, after being denied a request to reduce his bail, set at $500,000, in February. Sentencing is scheduled for Aug. 27.