In last month, mass shootings claim 53 lives

A string of shootings in the U.S. in the last month alone has claimed the lives of 53 people:

_MARCH 10, SAMSON, Ala. A gunman kills 10 people and commits suicide in a rampage that spanned two dozen miles across the southern Alabama countryside. Police say Michael McLendon had struggled to keep a job and left behind lists of employers and co-workers he believed had wronged him.

_MARCH 22, OAKLAND, Calif. A man pulled over in a routine traffic stop fatally shoots two officers and then kills two more in a gunfight in which the suspect was also killed. Relatives say Lovelle Mixon, 26, had been frustrated about not finding work and feared returning to jail.

_MARCH 29, SANTA CLARA, Calif. A man shoots and kills his two children and three other relatives, then kills himself at a family housewarming party in an upscale neighborhood. Investigators don't yet know the motive of Devan Kalathat, a 42-year-old engineer at Yahoo.

_MARCH 29, CARTHAGE, N.C. A man opens fire in a nursing home and kills seven elderly residents and a nurse who cared for them. Investigators say Robert Stewart, 45, apparently had targeted an estranged wife, a nurse's assistant who escaped by hiding in a bathroom.

_APRIL 3, BINGHAMTON, N.Y. A gunman bursts into an immigrant center and kills 13 people before killing himself. Police say Jiverly Wong, a 41-year-old Vietnamese immigrant, was apparently upset about losing his job and about people picking on him for his limited English.

_APRIL 4, PITTSBURGH A gunman wearing a bulletproof vest opens fire on officers responding to a domestic disturbance call, killing three of them. Police say Richard Poplawski, 23, had been upset about losing his job and feared the Obama administration was poised to ban guns.

_APRIL 4, GRAHAM, Wash. A man fatally shoots his five children in their mobile home and then takes his own life in his car miles away. Relatives identified the father as James Harrison. A motive was not yet known.