The shooting happened about 2:19 p.m. as people were exiting a funeral at SS Monica and Luke Catholic Church, located at 645 Rhode Island Court, according to Gary police.
Police said an unidentified light skin Black male shouted at the crowd moments before he began shooting. The gunman then fled the scene on foot, police said.
Officers arrived on scene to find a 41-year-old Merrillville man unresponsive outside the church, police said. He was transported to Methodist Hospital Northlake where he was pronounced dead.
Police said another 41-year-old man from Gary was found inside the church with a gunshot wound. He was transported to the same hospital and was listed in stabile condition.
Anyone with information is urged to call Lake County Metro Homicide Unit at 219-755-3866 or the Gary Police Department Tip Line at 1-866-CRIME GP.