Thu, Mar 22, 2012 12:59 PM EDT

A two-week old petition started by Trayvon Martin's parents, Tracy Martin and Sybrina Fulton, surpassed the one millionth signature mark Thursday morning.

"Please join us in calling on Norman Wolfinger, Florida's 18th District State's Attorney, to investigate my son's murder and prosecute George Zimmerman for the shooting and killing of Trayvon Martin," the parents wrote on