On Oct. 21, Philadelphia jeweler William Glatz was killed in a robbery at his store. He was the fourth U.S. jeweler killed during a robbery in 2010.

Police say that after an armed robber appeared at William Glatz Jewelers, Glatz and an employee took out their legally registered guns and a shootout ensued. The thief, escaped prisoner Kevin Turner, 22, was also killed. (His alleged accomplice, Obina Onyiah, 27, who reportedly fled the scene, was charged with murder Nov. 10.)

Also murdered in 2010 robberies: Henry Menahem of R.S. Durant in New York City (Jan. 27); David Pedigo of Pedigo ­Jewelers in Indianapolis (April 9); and John Lauseng of West Palm Coin and Jewelry in West Palm Beach, Fla. (July 26).

Bob Frank, vice president of the Jewelers’ Security Alliance, says although crime is generally down, homicides have risen. “Last year in the same period, we had two homicides,” he says. “Even so, they are nothing like they used to be. When I first came to the JSA, one year we had 37 homicides.” Frank says these incidents almost always occur after the jeweler resists. “When you resist, it’s a dangerous moment. I have said it a million times: They could line up all the jewelry in the world. I am not going to risk my life for that jewelry.”