In a shooting that occurred outside a Halloween party on University of Southern California has left four injured.

The shooting happened at the 'Freak or Geek' party organized by a student group. The injured were not students of USC.

The Los Angeles Times, citing law enforcement sources, identified the critically wounded man as Geno Hall, a former football star at Crenshaw High School in Los Angeles who in 2009 was ranked by the newspaper as a top local player.

Apparently, three others injured were hospitalized with non-life-threatening wounds.

According to witnesses, the men were waiting at the line with more than 100 people to get into the party when an argument broke out and one of them opened fire.

According to the university, unauthorized persons without student IDs are not allowed inside an on-campus party.

According to Associated Press, USC students were admitted free to this party, while those with a valid ID from another college had to pay. Costumed guests and fraternity and sorority members got a discount. A flier for the party noted there shouldn't be any worries because there would be campus police as well as 'strict off-duty officers.'

As USC police Capt. David Carlisle pointed out, the news of the party usually becomes viral through social networking sites inviting many unauthorized people to the venue.

"Although this incident did not involve USC students and was resolved quickly, it strikes at the heart of the Trojan Family," University President C.L. Max Nikias wrote in a statement, referring to the university's nickname.

"I understand the apprehensions and concerns of our campus community as we move forward."

Earlier this year, two USC Chinese students were killed near the campus.

Though USC students are satisfied with the security provided by the university, the proximity of the campus to downtown Los Angeles is posing a threat to the well-being of campus community.

Following the Halloween incident, the university announced Wednesday that it is set to review the security policies to make them more stringent.

"All of us have been shaken by serious incidents this year. Despite these events, or indeed because of them, we must continue to support each other as members of the Trojan Family," Nikias wrote.