A 31-year-old man is in critical condition after being shot by a 47-year-old man during a fight outside a junior varsity football game in Carrollton Thursday night.

Police Chief Derick Miller said no students were injured or involved in the shooting in the Hebron High School stadium parking lot.

Police said both men were sitting in the home stands of the JV game between Hebron and Irving Nimitz when the argument began. The men decided to take their disagreement to the parking lot and that's where one of the men pulled out a gun and shot the other.

Several witnesses, police said, supported the 47-year-old man's account that he was acting in self defense when he shot the other man in the upper chest. The injured man, who is expected to survive, was taken to Texas Health Presbyterian Hospital of Plano where he is listed in critical condition.

Police said in a statement Friday afternoon that they are referring the case to a Denton County grand jury and that the shooter is free pending the decision of the grand jury.

In a note to parents Friday, Hebron High School principal Scot Finch said the school is reviewing their security procedures to determine if any necessary enhancements need to be made for school events.

Finch said additional security measures were in place on campus Friday, even though the incident did not involve any students.

The Hebron and Irving Nimitz varsity squads took the field Friday night, as scheduled. Irving ISD says it increased its security presense.