The victim, a 28-year-old man, was stabbed outside the restaurant around 5 p.m., Prince George's County Police spokeswoman Jennifer Donelan said at a news conference Monday. He had been in line for a chicken sandwich when he and another man got into a fight, spilling onto the street, Donelan said. Police believe the argument began that someone happened to be in line.
"For you to get so angry with everything … and to develop into this kind of violence, again, is a very sad and tragic day," Donelan said.
Officers arriving at the scene took life-saving measures until the man was transported to a local hospital, where he was pronounced dead, Donelan said.
Police are still looking for the suspect. Donelan asked the suspect and people who were at the restaurant at that time to reach out to detectives.
"We are looking for a man and that man knows who he is," Donelan said. "He knows what he did here tonight and he needs to do the right thing and he needs to step up and settle in."
CNN has reached out to Popeyes for a statement.