CHARLOTTE, N.C. (FOX 46 CHARLOTTE) – The weapon used in a shooting that killed two students and injured four others at the University of North Carolina at Charlotte was purchased legally, authorities said.

Charlotte-Mecklenburg Chief of Police Kerr Putney said the weapon was a handgun and that the suspect had “quite a bit of ammo.”

According to police, the suspect entered Kennedy Hall and began firing into a lecture hall.

“The shooters choice of building was by design,” Putney said during a press conference Wednesday. “[The shooter] had some familiarity with the location.”

The shooting Tuesday claimed the life of two students, 21-year-old Riley Howell, of Waynesville, and 19-year-old Ellis Parlier, of Midland.

Howell tackled the gunman when he started shooting in his classroom, sacrificing his own life to save others, police said.

Four other students were injured in the shooting, 19-year-old Drew Pescaro, 20-year-old Sean DeHart, 20-year-old Rami Alramadhan, and 23-year-old Emily Houpt. Those students were recovering, according to UNCC Chancellor Phillip Dubois.

The suspect, 22-year-old Trystan Terrell, was arrested and charged with two counts of murder, four counts of attempted murder, four counts of assault with a deadly weapon with intent to kill, possession of a firearm on educational property, and discahrging a firearm on educational property.

Authorities said they are not investigating any other person in the shooting.

What was most troubling about the attack, according to Putney, was that there were “no warnings at all” that the attack was about to take place.

“I personally think we’ve made safety and security here a top priority since I’ve been here, since I’ve been chancellor,” Dubois said. “I think we’ve done everything I could imagine. I don’t think you can stop a determined assailant and also have an open campus.”

The campus remained on lockdown for 12 hours following the shooting. Kennedy Hall remained closed Wednesday as an active crime scene.

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