(CNN) -- The preteen shooter who opened fire inside a crowded middle school gym with a shotgun may have warned some students not to go to school before the attack, police in New Mexico said.
The revelation is part of the many angles police are looking into after Tuesday's shooting that left two students wounded, a New Mexico community stunned and a nation again wondering about the safety of its schoolchildren.
"We have preliminary information that possibly some of the students were warned by the individual prior to the shooting not to go to school," said New Mexico State Police Chief Pete Kassetas during a news conference Tuesday night.
He did not elaborate.
Police were executing three search warrants, Kassetas said: for the seventh-grade suspect's school locker, the bag he brought to the school and his home.
"We've got the individual we believe is responsible in state police custody," he said.
What police don't yet have is a motive.
Student Jordan Moody, who described himself as "friendly" with the suspected shooter, said he wasn't aware of any bullying or any other reason for the shooting.
"He just ran in there and just shot, really," Jordan said on CNN's "New Day" on Wednesday.
Searching for answers
The shooting occurred early Tuesday morning at Berrendo Middle School in the city of Roswell.
Police said the 12-year-old suspect, whose identity has not been released, entered the middle school gym, pulled a shotgun out of a bag and opened fire on students waiting for school to start. Two were wounded.
"We've confirmed that it is a 20-gauge shotgun," Kassetas said. "That the wood stock was sawed off."
A 13-year-old girl, Kendal Sanders, was in stable condition Tuesday night following surgery, New Mexico Gov. Susana Martinez said. Kendal suffered injuries to her right shoulder.
A boy, 11, was in critical condition, and underwent two surgeries. He suffered injuries to the side of his face and neck, the governor said.
The attack lasted about 10 seconds. It might have gone on longer, authorities say, were it not for the actions of a social studies teacher.
The teacher, John Masterson, walked up to the shooter and persuaded him to put the gun down, Martinez said.
"Mr. Masterson ... was a hero ... who stood there and allowed a gun to be pointed right at him," the governor said at a vigil Tuesday evening, "and to talk down that young boy to drop the gun so that there would be no more young kids hurt."
The Berrendo staff directory lists John Masterson as an eighth-grade social studies teacher.
Masterson has taught at the school for a decade, and also coaches track and soccer, according to the Albuquerque Journal.
When contacted by the newspaper, he said police told him not to discuss details of the shooting.
"It was a harrowing experience," he told the paper. "All I can say was the staff there did a great job."
Another school shooting
The attack understandably has rattled residents of Roswell, a city of just under 50,000 people 200 miles southeast of Albuquerque. The shooting puts Roswell on a growing list of places scarred by school shootings.
There will be no school Wednesday as police continue to investigate and the community tries to heal.
"I was in shock when I seen it," said 13-year-old Monique Salcido, who was in the gym during the shooting.
Monique told CNN's Piers Morgan she saw the shooter shoot two of her friends in those terrifying moments.
"I don't want to go to Berrendo again because I'm afraid it's going to happen again," she said.