This weekend, two University of California-Santa Cruz scientists who use animals in their experiments were the target of two separate bombings. One scientist who uses mice in his research on brain development had a firebomb ignited on his front porch while he and his family were home early Saturday morning. The other researcher’s unoccupied car was bombed. So far, no animal-rights groups have claimed responsibility for the bombings, but authorities are investigating possible connections since the scientist whose house was bombed was one of 13 UCSC scientists named in a menacing brochure apparently distributed by an animal-rights group that revealed the scientists’ names and addresses and read, “Animal abusers everywhere beware. We know where you live.” Though no one was killed in the attacks — the scientist and his family escaped through a second-floor window — the bombing of the scientist’s house appears to mark the first time an occupied building has been the target of animal-rights group actions; such groups typically rely purely on vandalism and intimidation. The house bombing is being investigated as attempted murder.