ST. LOUIS – St. Louis Police and federal authorities are combing through evidence yielded from searches of the home and car of the gunman in Monday morning’s mass shooting at Central Visual and Performing Arts High School in south St. Louis. The goal of it all is to prevent the next school shooting.

Police identified the gunman as Orlando Harris, 19, of south St. Louis. He graduated from the school last year and was intent on carrying out a massacre there, according to police.

“The individual had almost a dozen 30-round high capacity magazines on him. That’s a whole lot of victims there,” interim St. Louis Police Chief Michael Sack said.

Police were on the scene and made immediate entry into the school within four minutes of the first “active shooter” call, Sack said. Officers killed Harris in an exchange of gunfire.

Harris killed a female student, 16, and a female teacher, 61, police said. Six other students, ages 15-16, were wounded, three by gunfire. Another student fractured an ankle. She was among those jumping from a third-floor window to keep from being shot, police said. One student was initially listed in serious condition, but by Monday evening, none of the injuries were considered life-threatening.

The FBI and ATF conducted a search of Harris’s home and his car, which was outside the school. Officials are looking into items from the car that may have served as some sort of manifesto or list of past school shootings and shooters.

“I’m not really sure what might have been there. I know there was some evidence that was taken out of the vehicle,” Sack said.

A motive is not yet clear, but Harris broke in with his rifle drawn, police said. He was reportedly telling others this was the day they were going to die.

He had no adult criminal record, according to police. Investigators are looking into whether mental illness was a factor.

St. Louis FBI Special Agent in Charge Jay Greenburg issued a warning regarding an increase in “chatter” about more school shootings.

“Since this happened this morning, we have received an uptick in additional allegations of potential school shooters around here,” he said. “Any hoax or any joke that they’re sending about a school shooting right now will be taken very seriously.”

The FBI has also started a digital evidence collection website. Anyone with a digital photo, video, audio, or otherwise can upload it directly to authorities here.