The suspect arrested in connection to the Halloween shooting on the University of Southern California campus is a security guard, according to booking records and police.  

Brandon Spencer, 19, is suspected of wounding four people and was arrested on Thursday, Nov. 1, on the USC campus. Authorities on Thursday mentioned that they arrested two people in connection to the shooting, though it has not been confirmed whether the second person is still being held. 

The shooting took place outside of a Halloween party on the USC campus, and it was the first shooting on the campus in at least two decades, according to The Los Angeles Times. They also noted that the incident occurred due to an arguement between two people not affiliated with the school. Police and USC officials said the gunman opened fire on a man named Geno Hall, who was hit seven times but is expected to live, and three other bystanders that suffered wounds that were not life-threatening.

Hall plays football at West Los Angeles community college. He was taken to the hospital and remains in critical condition, ABC reported on Thursday. 

Neither the victims nor the two man detained by police in connection to the crime were USC students, according to The Associated Press. The shooting also has school officials questioning security measure on the campus; USC administrators said they are reviewing policies regarding visitors and events on campus. 

"While the risk of such an episode on campus is very low, it reminds all of us that we must look out for ourselves and be particularly vigilant about the personal safety of friends and guests at our social events," USC President C.L. Max Nikias said. 

USC Police Capt. David Carlisle said that people were waiting on line to get into the "Freak or Geek" Halloween party, organized by the school's Black Student Assembley, when the arguement broke out and one man pulled out a gun and opened fire. The incident took place at approximately 11:30 p.m. on Oct. 31 on an area of the school's Tutor Campus Center, ABC reported.