Federal authorities have expanded the investigation into a series of killings that have shaken the city of Stockton California. Police linked two more shootings to those of five killed between July 8 and Sept. 27, saying they may be "interconnected." A combination of video surveillance or ballistics led authorities to conclude that those slayings and the two additional shootings, including one in Oakland, are connected. Stockton police spokesperson Joe Silva said: "Last night was the new link that expanded to Oakland Our officers are going back to more old cases we have, and they're also, obviously, reaching out to other regional law enforcement agencies to see if they've had any type of similar cases." The San Joaquin County medical examiner's office identified the five victims of the July through September shootings as: 35-year-old Paul Alexander Yaw of Stockton, who died July 8; 43-year-old Salvador Debudey Jr., 43 of Stockton, who died Aug. 11;