(CNN) -- Police arrested a suspect early Saturday in the fatal shooting at South Carolina State University. Justin Bernard Singleton, 19, was charged with Friday's murder of 20-year-old student Brandon Robinson, according to a statement from the South Carolina Law Enforcement Division.
The two were arguing, when Singleton pulled out a gun and fired at Robinson, hitting him in the neck, police said.
After the shooting in Orangeburg County, police initially started an manhunt for a total of four possible suspects.
"He was a very nice young man," university President Thomas Elzey said of Robinson, fighting back tears in a brief statement to reporters Friday. "And it hurts. It hurts us all."
Elzey said "we are pulling together as a community," announcing that counselors would be made available to grieving students.
"Our first order of business is to make sure that our students are safe," the school president said.
Campus police were called to the Andrew Hugine Suites Living and Learning community about 1:30 p.m. and found the injured student, the university said. Police said eyewitnesses identified four suspects who had left the campus, the university said.
The school was initially put on lockdown; those restrictions were lifted a few hours later. Nonetheless, South Carolina State's Facebook page still urged people to "remain cautious and report any suspicious activity to police."
South Carolina State is a historically black university with about 4,000 students, according to the school website. The campus is about 40 miles south of Columbia.
CNN first learned about the incident via Twitter.
This is at least the third campus shooting this week.
On Tuesday, a gunman shot and killed another student inside Purdue University's electrical engineering building. Police said Cody Cousins, 23, an engineering student, killed Andrew Bolt, 21, of West Bend, Wisconsin. Cousins was charged with murder.
On Monday, a student was shot and critically injured near a gym at Widener University near Philadelphia. Police were looking for a suspect.
On Wednesday, the University of Oklahoma in Norman briefly shut down after a report of a possible shooting that apparently turned out to be a false alarm, the university's president said.