A 25-year-old man is being questioned in connection to the cold-blooded slaying of a young woman working at an East Harlem Burger King, cops said early Friday.

Police confirmed that the man — whose exact connection to the case is not immediately known — was being interviewed at the 25th Precinct Friday morning, days after 19-year-old Kristal Bayron-Nieves was shot dead at the fast-food joint at East 116th Street and Lexington Avenue.

Krystal Bayron
Kristal Bayron-Nievex was shot dead at just 19 years old.
G.N.Miller/NYPost

The incident unfolded around 1 a.m. Sunday, when an armed robber walked in and pistol-whipped a male customer before punching a female manager in the face, cops said.

Bayron-Nieves gave the robber cash from the drawer, an eyewitness said, according to her mother. The thief then turned to leave but whipped around again and shot Bayron-Nieves in the torso, the witness said.

The killer got away with just $100, the victim's family said.

burger king murder
The robber turned around and shot Kristal Bayron-Nieves even after she gave him money.
DCPI

The teenager was taken to Metropolitan Hospital, where she was pronounced dead a short time later, cops said.

The NYPD announced earlier this week that it is offering a $10,000 reward for any information that leads to the arrest and indictment of Bayron-Nieves' killer.

Billionaire supermarket mogul John Catsimatidis is offering his own reward of $10,000.