Jury sees gun that killed Trayvon Martin in George Zimmerman murder trial

Jurors were shown a slew of evidence Tuesday in the murder trial of George Zimmerman, including the 9-mm. handgun used to fatally shoot Florida teen Trayvon Martin, as witnesses for the prosecution took the stand for a second day.

Diana Smith, a crime scene technician for the Sanford Police Department, testified Tuesday as prosecutors introduced photographs of the crime scene and evidence collected by the police.

Jurors were shown a can of Arizona Iced Tea and a bag of Skittles, the items Martin bought at a convenience store on the night he was killed.

The prosecution also introduced photographs taken of Zimmerman after the shooting that appeared to show him with a bloody nose, blood dripping behind his ear and lumps and a cut on the back of his head.

The six female jurors paid close attention as Smith held up the firearm that belonged to Zimmerman – the same one used to fatally shoot the 17-year-old.

SPECIAL COVERAGE: ZIMMERMAN TRIAL

The seventh witness called in the trial was Sgt. Tony Raimondo, a veteran police officer and former Marine who arrived on the scene shortly after Martin was shot.

The prosecution showed jurors graphic photos of the dead teen as the Sanford police sergeant described bubbling sounds that came from the teen's bullet wound. Raimondo testified he tried to seal the bullet wound in Martin's chest with a plastic bag and attempted mouth-to-mouth resuscitation, but Martin was pronounced dead a short time later.

Martin's father, Tracy Martin, walked out of the courtroom as prosecutors showed photographs of Martin's dead body -- one of him lying face-down in the grass, another of his body face up with his eyes slightly open, and a third of the bullet wound.

Also testifying was a neighbor who partially witnessed the struggle between Zimmerman and Martin, stating that she heard shouts of "no" during the fight. Selene Bahadoor's testimony was the first by someone who witnessed some of the confrontation that resulted in Martin being fatally shot.

Bahadoor said she heard the sound of running outside her home, and when she looked out a window she saw arms flailing in the dark. She left to turn off a stove and then heard a gunshot. Bahadoor said she saw a body on the ground the next time she looked out the window.

Wendy Dorival, the former coordinator of the Sanford Police Department's neighborhood watch program, testified Tuesday how she had worked with Zimmerman to set up a watch program in his neighborhood, The Retreat at Twin Lakes.

When asked by prosecutor John Guy if neighborhood watch participants should either follow or engage with suspicious people, she answered "no."

"They are the eyes and ears of law enforcement," said Dorival. "They're not supposed to take matters into their own hands."

But Dorival said she was impressed with Zimmerman's professionalism and dedication to his community and asked him to join another program, Citizens on Patrol, which trained residents to patrol their neighborhoods. He declined.

"He seemed like he really wanted to make changes in his community, to make it better," Dorival said.

The president of Zimmerman's homeowners association also testified that Zimmerman was in charge of the neighborhood watch program started in his townhome complex. He said Zimmerman was the person who went through a class offered by Sanford police to get it started.

Donald O'Brien said he also attended a neighborhood watch meeting led by Zimmerman and it was O'Brien's understanding that participating residents "were supposed to stay away" from suspicious activity and "call the police."

"Do not get close to anybody," O'Brien said of what he understood about neighborhood watch. "Stay at a safe distance and call 911. Let the police handle it."

The jury must decide whether Zimmerman shot and killed the 17-year-old African-American teen in self defense, or if he stalked the youth and provoked the deadly 2012 confrontation.

Zimmerman could face life in prison if convicted on the second-degree murder charges.

Earlier Tuesday, prosecutors pushed to introduce recordings of non-emergency calls Zimmerman made to police over an eight-year period.

Zimmerman, 29, called the police close to 50 times over an eight-year period to report such things as slow vehicles, loitering strangers in the neighborhood and open garages.

Prosecutors want to introduce recordings of five of those calls, saying they are indicative of Zimmerman's overzealousness in pursuing people he considered to be suspicious - and of his state of mind on the night he shot unarmed teen.

Judge Debra Nelson delayed ruling on the matter.

The Associated Press and Reuters contributed to this report.