An Orleans Parish judge calls a mistrial in a murder case because the defense lawyer had just learned prosecutors had the alleged murder weapon.

The Times-Picayune reports that 19-year-old Kendell Stewart remains jailed on $500,000 bond. He's charged with helping kill 15-year-old Javonte Morgan outside a fast-food restaurant the night of Feb. 3, 2008.

Criminal District Judge Julian Parker rescheduled trial in October.

Prosecutors have said since 2008 that police never found the 9-mm handgun.

Defense attorney Jason Williams said he learned Wednesday that it had been in state custody since 2008, from another case.

Court rules let the defense test physical evidence long before trial.

Prosecutor Eusi Phillips said he only learned this week that police had the gun.