patsyiskul: Witness recalls efforts to save wounded Trayvon Martin

LIVE VIDEO ? George Zimmerman faces charges of second-degree murder in the shooting death of Trayvon Martin.

By James Novogrod, Tom Winter and Tracy Connor, NBC News

The jury in the George Zimmerman trial was shown photos Tuesday of Trayvon Martin?s body and a closeup of a chest wound as a police sergeant testified about his attempts to save the teenager?s life.

Sgt. Anthony Raimondo of the Sanford, Fla., police department told jurors how he arrived at the shooting scene, in the evening drizzle, on Feb. 26, 2012, to find Zimmerman handcuffed by another officer.

Martin?s body was on the grass, facedown with his hands under him, Raimondo said.

He said he checked the 17-year-old for a pulse and found none and then turned him over to perform CPR.?

?I breathed for Mr. Martin -- or I tried to,? Raimondo said, adding that the other officer performed the chest compressions.

Editor's note: Photos from the crime scene, which some readers might find disturbing, are included below.

Raimondo said there was a bubbling noise ? the sound of air escaping from the chest wound -- and he asked for plastic wrap and Vaseline so he could create an airtight seal around it. A passerby brought him a plastic bag.

The sergeant testified that he sat the body upright to feel for an exit wound and felt a cold can in Martin?s hooded sweatshirt pocket ? the Arizona brand fruit drink he had purchased at a 7-Eleven where he also bought Skittles for a his father?s girlfriend?s young son.

Raimondo laid the body back down to continue CPR, but could not revive Martin. After a rescue crew arrived and pronounced Martin dead, Raimondo put an emergency blanket over the body, he testified.

While the 14-year veteran was on the stand, prosecutors displayed pictures of Martin?s body facedown on the grass, face-up after the CPR attempt, and under the emergency blanket. There was also a photo of what appeared to be a coin-sized chest wound. Martin?s father left the courtroom as the pictures were shown.

It was the most graphic evidence to date in the trial, which began in earnest Monday with opening statements. Zimmerman has pleaded not guilty to second-degree murder, claiming he shot Martin in self-defense.

Earlier testimony on Tuesday focused on Zimmerman?s experience with a neighborhood watch program, with a ?civilian employee for the Sanford, Fla., police department saying he struck her as ?meek? but civic-minded and ?professional.?

Wendy Dorival said that as part of her job, she assisted neighborhood watch programs, which enlist residents to be the ?eyes and ears? of the police department and alert authorities to suspicious activity.

Dorival met with Zimmerman in September 2011 to help him launch a neighborhood watch, and later tried to recruit him for the Citizens on Patrol program -- a more intensive volunteer squad that offers training, uniforms, and a vehicle to participants. He declined, she said.

?He seemed a little meek,? Dorival testified under cross-examination on the second day of testimony in the second-degree murder trial. ?He seemed like he really wanted to make changes in his community to make it better.?

Sanford Police Dept.

This crime scene photo presented by prosecutors for the State of Florida shows Trayvon Martin's body from the night of the shooting in February 2012. The photo was entered as evidence during George Zimmerman's trial in Seminole circuit court June 25, 2013 in Sanford, Fla.

Dorival was put on the stand by prosecutors, who contend Zimmerman ?profiled? Martin as the unarmed teen walked through a gated community on Feb. 26, 2012, then shot him through the heart during a confrontation.

The defense says Martin, 17, was the aggressor and ?viciously? attacked Zimmerman, 29, forcing him to shoot in self-defense.

Dorival said she tells neighborhood watch volunteers like Zimmerman they are observers who alert police to possible problems and don?t take action themselves.

Asked what watch volunteers are told about following and confronting people, Dorival said, ?We tell them don?t do that. That?s the job of law enforcement.?

A handbook that Dorival gave to watch groups, which was shown to her on the stand, contained a page that read: "Neighborhood watch is not the vigilante police."

When she was questioned by the defense, Dorival had mainly positive things to say about her contacts with Zimmerman, calling him professional. She also said he wrote a complimentary letter about her to the police chief and that she thanked him for it.

Prosecutors want to play for the jury five calls that Zimmerman made to a non-emergency police dispatcher between August 2011 and Feb. 2, 2012 to report people or activity he found suspicious.

They said the prior calls would give the jury insight into Zimmerman?s state of mind when he encountered Martin, which is important since Florida law requires proof of a so-called "depraved mind? for a second-degree murder conviction.

The defense contends that the prior calls have no bearing on Zimmerman?s fatal confrontation with Martin.

The judge has not yet ruled on whether the jury can hear the calls.

Editor?s note: George Zimmerman has sued NBC Universal for defamation. The company has strongly denied the allegations.