Martin is scheduled to be sentenced March 4 and could face more than 200 years in prison, based on the maximum penalties for the charges under Indiana law. Each conviction of attempted murder could result in a 50-year sentence.
Martin and a second man, 24-year-old Traneilous Jackson, were accused of opening fire Sept. 9 on the ambulance and a car following it as the ambulance transported a man who had been stabbed during a fight at the Piere's nightclub complex on St. Joe Road.
Each vehicle was hit with 16 to 20 gunshots and three women in the car and a medic suffered injuries. About 10 bullets hit one woman in the car, according to court documents. The medic was cut by shattered glass, shrapnel and bullet fragments, the documents said.
Defense attorneys argued witnesses who testified against Martin did so under plea deals with prosecutors.
Jackson pleaded guilty to seven charges, including four counts of attempted murder, last week and faces up to 60 years in prison when sentenced. His sentencing is scheduled for Feb. 25.