NEW YORK — New York City's mayor criticized the top US gun lobbying group after three of the city's police officers were shot in separate incidents that left one suspect dead and four under arrest. The shootings occurred in a one-hour span Thursday night. “In recent weeks, we've heard some people say that the only thing that stops a bad guy with a gun is a good guy with a gun. But sometimes the good guys get shot — and sometimes, they are killed,” Mayor Michael Bloomberg told reporters Thursday. Bloomberg is very outspoken on gun violence and has been critical of the National Rifle Association's suggestion last month that the solution to school shootings like the recent one in Newtown, Connecticut, should be addressed by putting an armed police officer in every school in the country. The Newtown shooting killed 20 children, ages 6 and 7, along with six adults at the school. On Thursday, off-duty Police Officer Juan Pichardo was shot in the thigh at his family's car dealership. An hour later, two plainclothes transit officers were injured in a shootout on a subway car. One of the officers returned fire, killing the suspect. Last year, 11 of the city's police officers were shot while on duty and one while off duty, none of them fatal. Debate over US gun laws raged last month following the massacre of 20 first-grade students and six teachers at Sandy Hook Elementary School in Newtown, Connecticut, by an unhinged teenager using a Bushmaster assault rifle. President Barack Obama said at the time that America must act to prevent such massacres, but reform of gun laws is politically unpalatable given that the right to bear arms is preserved in the US constitution. — AP