The number of police officers killed in the line of duty jumped 37 percent in 2010, up to 160 from a 50-year low of 117 last year. Contributing to this year’s total, which is closer to the norm, were a number of so-called cluster killings, in which several officers were killed in one incident. Police deaths were spread across 30 states and Puerto Rico, with the California Highway Patrol and the Chicago Police Department leading the pack. In 2010, 59 police officers were killed by gunfire, up from 49 in 2009. This year’s total is still significantly lower than in 2001, when 240 officers were killed in the line of duty.