Man shot by off-duty NYPD officer in the Bronx, police say

Man shot by off-duty cop in the Bronx

It's not clear what led to the shooting and the incident remains under investigation. 

NEW YORK - A man was shot in the head by an off-duty NYPD officer Monday night in the Bronx, police said.

What we know:

The shooting happened just after 9 p.m. outside 167 W. 231st St. in the Kingsbridge section.

Authorities said the off-duty officer fired, striking the 30-year-old man in the head. 

The circumstances leading up to the shooting were not immediately clear, including whether it may have stemmed from a robbery attempt or another encounter.

The victim was taken to a nearby hospital, where he remained in critical condition Tuesday morning.

What we don't know:

It's unclear what led to the shooting. The identities of the individuals involved remain unknown. 

The investigation remains ongoing.