Livingston removed a can from Martin's sweatshirt. She also heard a small bag that made a "crinkling noise" but didn't move it. She saw a gunshot wound in his chest.
"We put on a cardiac monitor to access the heart rhythm. It was determined by the lead paramedic on the scene that the rhythm was incompatible with life," said Livingston.
Martin was pronounced dead at 7:30 p.m. Her unit didn't transport his body.
[Updated at 2:16 p.m. ET]
Livingston's unit was dispatched at 7:21 p.m. ET. She arrived about six minutes later and checked Martin for a pulse on his neck.
[Updated at 2:14 p.m. ET]
The prosecution has called Stacey Livingston to the witness stand. She's an EMT and firefighter for the Sanford Fire Department.
[Updated at 2:11 p.m. ET]
Zimmerman was compliant, according to Ayala, and he didn't disobey in any form. O'Mara has finished his direct examination. The witness has been excused.
[Updated at 2:08 p.m. ET]
Ayala says he arrived so quickly on scene that the other officer still had Zimmerman at gunpoint. He says this is protocol if shots have been fired.
[Updated at 2:06 p.m. ET]
Prosecutor Guy has concluded his direct examination. Now defense attorney O'Mara has started his direct examination.
[Updated at 2:05 p.m. ET]
"At any time, did you see any signs of life from Trayvon Martin's body?" asked prosecutor John Guy.
"No, sir," said Ayala.
He was performing chest compressions. Eventually, he says, emergency personal arrived and pronounced Martin dead on the scene.
[Updated at 2:04 p.m. ET]
Ayala worked with another officer to roll Martin's body over.
"Underneath -- he had a pin or button -- it was underneath the button," said Ayala about the gunshot wound.
Ayala and another officer started CPR on Martin.
[Updated at 2:02 p.m. ET]
Ayala says he was the first officer to approach Martin, who was face-down with his hand beneath him.
"I asked to see his hands," said Ayala. Martin didn't respond physically or verbally to his commands. He didn't see any movement or hear any sounds from the body.
[Updated at 1:59 p.m. ET]
The prosecution has called Ricardo Ayala, a police officer with the Sanford Police Department, to the witness stand. He responded to the shooting that night. He demonstrates on a map where he entered the neighborhood and where he parked.
[Updated at 1:55 p.m. ET]
The defense has no more questions, and Manalo is being excused.
[Updated at 1:54 p.m. ET]
Manalo says he didn't see the actual shooting take place and can't say if it's self-defense. The prosecutor has finished his redirect examination.
[Updated at 1:53 p.m. ET]
The prosecutor again asks about Zimmerman's demeanor.
"Coherent, compliant -- he wasn't ... he was calm. He was staggering a little bit," said Manalo.
[Updated at 1:52 p.m. ET]
Defense attorney West has wrapped his cross-examination. Prosecutor de la Rionda is now asking more questions.
[Updated at 1:49 p.m. ET]
A flashlight next to Martin's body caught Manalo's eye, so he took a photo of that as well, which is being displayed again in court. Manalo describes where he was standing when he took the photos.
[Updated at 1:46 p.m. ET]
Defense attorney West pulls up the photo Manalo took of Martin's body. Manalo says the body position is how he saw it when he arrived -- Martin face-down on the ground. He says he used a flashlight to illuminate the scene.
[Updated at 1:43 p.m. ET]