An NYPD cop investigating a former shooting case was shot on Tuesday while chasing a man in the Bronx. He was wearing plain clothes. 

At around 10:30 p.m., the 31-year-old male officer, with the department's gun violence suppression unit, was hit in the back near Lafayette Avenue and White Plains Road in Soundview.

When the 24-year-old suspect, who is known to the department, fled after he learned they had noticed him, the victim and three fellow officers were driving near the intersection, the sources said.

NYPD Commissioner Dermot Shea said at an early Wednesday press conference that it is suspected the police exchanged bullets with the suspect during the chase.

Shea added, "In the course of seconds, what we know is that our officer, we believe fired one round. We believe the perpetrator fired four rounds. The cop who was struck, a six-year veteran with the department, was wearing a vest at the time, but was struck just below the protective gear."
 

The victim was taken to nearby hospital and remains in a stable condition.