DNA tests released Wednesday show that Trayvon Martin’s DNA was not found on the handgun that George Zimmerman killed him with, reports the Los Angeles Times. The revelation could undermine Zimmerman’s self-defense claim in his murder trial.

The tests performed by the Florida Department of Law Enforcement found only Zimmerman’s DNA on the weapon and the holster. It could not be determined whether Martin’s DNA was on the gun holster. It’s been widely reported that Zimmerman will plead self-defense to the charge of second-degree murder, a decision that’s now being questioned because Zimmerman had claimed that Martin reached for the gun.

Zimmerman, 28, is currently free on bail and awaiting trial, which isn’t expected to start until early 2013. Martin, 16, was killed in Sanford, Florida on the night of Feb. 26. Zimmerman’s wife Shellie has been charged with perjury, although both are currently free on bond.

CBS News reported that Zimmerman’s attorneys are not planning to invoke Florida's “stand your ground” law, which allows people to use deadly force if they think their life is at risk. Martin was walking from a store to his father’s house unarmed. Zimmerman wasn’t arrested until 44 days after killing Martin, leading many to accuse the Sanford Police Department of racism because Martin was black while Zimmerman is Hispanic.

“The facts don’t seem to support a ‘stand your ground’ defense,” Zimmerman’s attorney Mark O’Mara told CBS News.

In the past Zimmerman said Martin knocked him down with a punch in the nose and then overpowered him, raining punches on his head and putting his hands over Zimmerman’s nose and mouth. At that point, Zimmerman claimed, he was able to reach for the gun and shoot Martin in the chest, according to the Associated Press.

The new DNA evidence is expected to play an important role in the murder trial.

Zimmerman last made headlines when, during an interview with Sean Hannity of Fox News, said he felt his killing of Martin was “God’s plan,” a statement that was met with much disgust around the country.

Florida