A gun expert found that bullets and shell casings from a 2006 shooting at Custer State Park came from a .40-caliber handgun tied to a Hells Angels biker standing trial.

Frans Maritz was the last state witness in the case against Chad Wilson of Lynnwood, Washington, and John Midmore of Valparaiso, Indiana, who are charged with trying to kill Outlaws Motorcycle Club bikers.

The defense lawyer said his clients acted in self defense.

The prosecution and defense stipulated that Maritz would testify that 12 shell casings and two bullets from the scene and four bullets from two of the people shot all match the handgun prosecutors said Wilson threw into a ditch as he fled the scene.

The defense plans to start calling witnesses after giving an opening statement Friday afternoon.