[Updated at 12:07 p.m. ET]
Siewert says she only examines clothing, she doesn't look at the wound a victim might have. O'Mara has finished his questions. Prosecutor John Guy asks if the gun could have been used for murder. The defense objects, and the judge sustains.
[Updated at 12:05 p.m. ET]
O'Mara says there was no evidence that the gun was pressed into the sweatshirt. Siewert says it was consistent with the firearm touching the shirt, whether that touch was light or more pressed into the shirt. She says there may potentially have been different evidence if the sweatshirt was wrapped around the gun.
[Updated at 12:01 p.m. ET]
Siewert says again that most law enforcement guns she sees have a bullet in the chamber.
[Updated at 11:59 a.m. ET]
Siewert agrees that most law enforcement carry guns with a bullet in the chamber.
"They're not much use if they're not ready to fire, are they?" asks O'Mara.
"No," says Siewert.
[Updated at 11:58 a.m. ET]
O'Mara asks if Zimmerman's gun is a safe one to carry loaded. "This gun, again in working order, is safe in terms of it will not fire unless the trigger is pulled," says Siewert. She says having a loaded gun be considered safe is a personal preference.
[Updated at 11:57 a.m. ET]
Siewert says the trigger on this gun in particular needs to be pulled back much farther than other guns. She says this feature potentially makes it safer.
[Updated at 11:56 a.m. ET]
O'Mara says that if someone were carrying a gun for self-defense, they would want it ready to fire and to not have a safety. Siewert says she believes that's personal preference.
[Updated at 11:53 a.m. ET]
Defense attorney O'Mara has Siewert hold Zimmerman's gun. She says that the "double action" aspect of the gun also works as a safety feature. She agrees that a double-action gun, when it's ready to fire, is safer to carry than a single-action gun that's ready to fire.
[Updated at 11:48 a.m. ET]
Siewert did the same test on Martin's inner shirt.
"This as well was consistent with residues and physical effects consistent with a contact shot," said Siewert. She says she believes the muzzle of the gun was against Martin's sweatshirt when it fired. The prosecution has finished its questions.
[Updated at 11:47 a.m. ET]
Zimmerman's gun and one of the live rounds was used by Siewert to conduct a test on part of the fabric from Martin's hooded sweatshirt.
"The clothing displayed residues and physical effects consistent with a contact shot," says Siewert.
[Updated at 11:44 a.m. ET]