India, Dec. 2 -- Authorities in California appealed to the public for tips, even rumours, as they searched on Sunday for a suspect in the killing of three children and an adult during a mass shooting at a child's birthday party in Stockton. "It's heartbreaking," said Heather Brent, a spokesperson for the San Joaquin County sheriff's office. She said investigators believe it was a "targeted incident" at a banquet hall where 100 people or more had gathered Saturday night. No one was in custody by Sunday afternoon, and she did not elaborate on why authorities believe it was intentional or who might have been targeted. "If you have surveillance footage, if you're a local business here, if you're in the area, live in the area, or maybe you've he...