Investigators say the intended target was a friend of Ortiz who was seated next to him and dressed similarly.
Officials say the gunman was shown a picture of the target minutes before the attack but became confused on who he was supposed to shoot.
Eleven people are currently in custody for the attempted murder of the Red Sox star, but law enforcement officials say the mastermind behind the shooting is still on the run.
Ortiz remains hospitalized from the gunshot wound to his back, but doctors have upgraded his condition.