PHOENIX (AP) - The most seriously wounded of three people shot in a community-college computer lab had punched the gunman, an old enemy, in the face before he opened fire, police said Friday.

Isaac Deshay Smith was sentenced to jail for attacking Rodney Smith in December, and the two unrelated men had gotten into verbal confrontations every time they met since then, Phoenix Detective Reuben Gonzales said.

On Thursday, police said, Isaac Smith, 19, punched 22-year-old Rodney Smith during a confrontation at South Mountain Community College.

Rodney Smith, like Isaac Smith a former student of the school, then pulled a handgun from his waist and opened fire, according to a probable cause statement released Friday. School officials say 20 to 30 people were in the lab, which is open to the public.

Isaac Smith was trying to hide under a table when he was shot, the court document said. Gonzales said the bullet entered his body through the groin area, traveled through his stomach and into his chest cavity. He underwent emergency surgery overnight and was 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, police said.

At a court appearance Friday, Rodney Smith pointedly apologized to the "innocent victims" of the shooting after the judge advised him that anything he said could be used against him in court.

"I didn't mean for any innocent victims to get hurt," he said. "I apologize to the innocent victims and their family."

Court documents say the December fight began after a man who was at a gas station with Isaac Smith tried talking to a woman who was with Rodney Smith. Isaac Smith and two others punched and kicked Rodney Smith repeatedly as he lay on the ground - breaking his jaw in two places - and the woman was punched in the stomach when she tried to stop them, documents say.

The three attackers pleaded guilty to felony aggravated assault. Isaac Smith was sentenced to three weekends in county jail and two years' probation, and was ordered to pay an unspecified amount of restitution to Rodney Smith.

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; bond was set at $200,000.

It was not known if Rodney Smith had a lawyer yet. There was no immediate response to a request for an interview made through the Maricopa County Sheriff's Office.

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.

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.