According to sources, police are investigating a shooting that left two officers wounded, seeking to determine if one was injured by “friendly fire.”Tab “Turk” Virgil Jr., 22, was charged with attempted murder, after officers were greeted with gunfire as they raided a Memphis, Tennessee apartment on Monday (January 26), seeking heroin.Deputy Jason Pagenkopf may have been shot in the neck by another officer returning fire.Pagenkopf was released from the hospital this week and is recuperating at home.The other officer shot, Chris Harris, remains in critical condition after surgery. Harris was shot in the jaw, hip and leg.Officials are waiting for ballistic and forensic test results to determine whose gun the bullet that struck Pagenkopf came from.If it is determined that the bullet came from a gun Virgil is accused of shooting, he may face additional charges.Virgil is being held in lieu of $1 million dollars bail.Over the past six months, six Memphis police officers have been shot, prompting police to review their tactics for serving warrants.