Animal rights groups are pushing for action after an off-duty Ridgefield police officer killed a bear on his Newtown property and was cleared of wrongdoing.  In May, a bear, nicknamed Bobbi, was shot, and killed by Lawrence Clarke. He told investigators the bear had been behaving aggressively, threatening his chickens and his grandson. The state Department of Energy and Environmental Protection cleared the officer of wrongdoing.  Newtown has an ordinance that forbids weapon from being discharged within 500 feet of a residence, but Chief David Kullgren says this case was an exception due to self defense.