Lil Wayne's New York gun case is set to begin on Wednesday (October 21), and according to reports, DNA testing is gonna be the prosecution's focus.

According to the Associated Press, Weezy's gun case will use DNA profiling to determine whether or not the weapon found on his tour bus in 2007 was his.

The technique is used to identify people from tiny amounts of DNA, said the report.

The 27-year-old rapper has pleaded not guilty to the charges, and could face at least 3 1/2 years in prison if convicted.

Wayne was arrested back in July 2007 while in New York headlining his first concert at the Beacon Theatre. Police pulled over his bus, following the show, and found a .40 caliber handgun and marijuana.

In a recent VH1 "Behind The Music" special on the rapper, his manager took responsibilty for the gun.