Screenshot via NBC News.
Sgt. Anthony Raimondo Jr., an agency veteran and SWAT sniper, immediately went to the teen's unresponsive body when arriving at the scene, checked twice for a pulse, and began performing CPR. Raimondo did mouth-to-mouth while a second officer did chest compressions.
"I breathed for Mr. Martin ... or I tried to, sir," he told prosecutor John Guy, reports the Miami Herald.
Zimmerman has been charged with second-degree murder in the fatal shooting.