SAN FRANCISCO Three robbery suspects who were allegedly inside a van that crashed and killed a city police officer during a chase were charged with murder Thursday, and a fourth was being held on suspicion of murder. Steven Wayne Petrilli, 19, of Hayward; Carl Lather, 20; and Nicholas Smith, 22; also were charged with manslaughter, evading police and robbery, according to the San Francisco District Attorney's office. Jessica Chamberlain, 20, who also was a passenger in the van, was arrested but not yet charged. Police are still trying to determine why officer Nick-Tomasito Birco, 39, joined in Wednesday's pursuit of...