George Zimmerman, right, talks with his attorneys Mark O'Mara, left, and Don West, center, during a recess on the 17th day of Zimmerman's trial in Seminole circuit court, Tuesday, July 2, 2013 in Sanford, Fla. Zimmerman has been charged with second-degree murder for the 2012 shooting death of Trayvon Martin. (AP Photo/Orlando Sentinel, Joe Burbank, Pool)

Expert: No Martin DNA on gun grip

The judge in the George Zimmerman murder trial will hear arguments from attorneys about whether to admit evidence about a college criminal j…