The incident happened in an apartment near the University of North Carolina at Chapel Hill campus on Tuesday.
The victims are Deah Shaddy Barakat, his wife Yusor Mohammad Abu-Salha, and her sister Razan Mohammad Abu-Salha.
Police arrested the shooter, identified as Craig Stephen Hicks.
The suspect, who is being held in the Durham County Jail, is charged with three counts of first-degree murder.
The Chapel Hill Police Department announced that "there is no ongoing threat to the public."
As a Syrian-American, Barakat was a doctoral student at the university’s School of Dentistry.
Carol Folt, the chancellor of the University of North Carolina, will issue a statement later on Wednesday.
"We understand you want to know the facts as quickly as possible. At the same time, we must respect the job our Chapel Hill police have as they investigate this crime," the school said.
People on social media quickly reacted to the shooting, posting pictures of the victims and claiming they had been “murdered execution style.”
Two hashtags went across twitter by the social network users, #chapelhillshooting and #MuslimLivesMatter.
On tweet said, “Muslim victims were recently seen providing free dental & food supplies to the poor & homeless."
Some users urged US President Barack Obama to condemn the incident, comparing the shooting to the Charlie Hebdo shootings in Paris.
More about:
