A 19-year-old man was shot Friday afternoon during an argument in a parking lot at the University Square Mall. Melvin Eugene Session of 3905 E Clifton St. was walking in a parking lot behind the mall with three other men about 3 p.m. when a Chevrolet Impala carrying four passengers pulled up, said sheriff's spokesman Jack Espinosa. One of the passengers got out and started arguing with the men. Then he pulled out a gun and shot Session once in the abdomen, Espinosa said. The car left but returned to the parking lot a second time, and the two groups began arguing again. Then the car left, Espinosa said. Officials don't know what the men were arguing about. Session underwent surgery at St. Joseph's Hospital and was in stable condition late Friday.