PHOENIX — One of three people wounded in a computer lab at a community college had punched the gunman in the face before he opened fire, police said Friday.

Isaac Smith, 19, had beaten the suspect, Rodney Smith, in a fistfight in December and the two had gotten into verbal confrontations every time they met since, Phoenix Detective Reuben Gonzales said.

On Thursday, police said, Isaac Smith punched 22-year-old Rodney Smith in the face during a confrontation at South Mountain Community College.

Rodney Smith, a former student at the school, responded by opening fire with a handgun, according to a probable cause statement released Friday. School officials say 20 to 30 people were in the lab at the time.

Isaac Smith was listed in critical condition Friday at Maricopa Medical Center. The other victims, identified as Otisha Charee Williams, 20, and Christopher Lee Taylor, 17, were in stable condition early Friday. Williams and Taylor appear to have been innocent bystanders, according to police.

Rodney Smith was arrested soon after the shootings at a home about three miles from campus. He was booked for investigation of aggravated assault, endangerment and misconduct involving weapons and made a brief appearance in court Friday where bond was set at $200,000. It was not known if he had a lawyer yet.

Smith's parents and three other people were arrested at the home on charges of interfering with an investigation and failure to obey a police officer after they crossed police tape and demanded to go back inside, Gonzales said.

Student Yessenia Lara, 18, said she saw one man punch another, then heard three shots. She said everyone else ducked, and the shooter ran off while the victims screamed in pain.

Smith was identified as a former student at the college, but details on when he attended were not immediately available.

College spokesman Robert Pryce said the school was in lockdown for about an hour because of Thursday's shootings, and as many as 300 people were on campus at the time.

"The safety of our students and staff is our highest priority and all appropriate measures are being taken to ensure the safety of our campus," college President Ken Atwater said in a statement. The statement did not elaborate.

Classes were canceled Thursday, and students could be seen leaving the campus calmly about 90 minutes after the shooting. The college was closed Friday as it typically is during the summer.

Situated at the base of Phoenix's South Mountain, the college has more than 8,000 students. Most students are seeking associate degrees and certificates of completion.