In Philadelphia, a student allegedly fired a handgun inside his high school gym, injuring at least two students.
One suspect is now in custody, but police say they are searching for additional suspects as well.
CNN's Jason Carroll has the story OutFront.
(CNN) – He had a 20-gauge pump shotgun, which police say he personally sawed off.
He had three shells.
And he had a plan.
The 12-year-old had all these when he entered a Roswell, New Mexico, middle school gymnasium and opened fire, State Police Chief Pete Kassetas said Wednesday.
His first shot, which Kassetas characterized as "birdshot," hit the ceiling. The second went into the gym floor. The third sped toward the stands where, some 12 to 15 feet away, it hit two of a throng of students who had been waiting for classes to start.
"The victims were random," the state police chief said.
Having carried out three search warrants and conducted at least 60 "primary interviews," Kassetas laid out these and other details related to Tuesday morning's shooting at Berrendo Middle School. But he didn't disclose everything, including the preteen shooter's possible motive.
"We did find evidence that the suspect had planned this event," Kassetas said. "I can't discuss the particulars as to why."
Senior Eric Waugh was also in class when he heard the shots ring out, and he comes OutFront tonight to describe the chaotic aftermath and how he thinks the school will rally around this tragedy.
A teenager opened fire in a Colorado high school Friday afternoon, injuring several students and killing himself a day before the one-year anniversary of the Sandy Hook Elementary School shooting that left 20 small children dead.
Three students were wounded, one seriously, at Arapahoe High School in Centennial, Colorado when the shooter opened fire with a shotgun.
According to the sheriff, the suspected shooter was targeting a specific teacher. Outfront tonight is Christian Jay Myers, a sophomore who was in class when he heard the gunshots.
Connecticut officials released a 44-page report Monday that outlines how 20-year-old Adam Lanza killed 20 young students and six staff members at Sandy Hook Elementary School last December.
Investigators say Lanza was obsessed with mass murders and even collected newspaper clippings about school shootings.
How did that not raise a red flag?
Criminologist Casey Jordan is OutFront.