HOUSTON – Investigators believe alcohol or narcotics was a factor when another vehicle struck a police patrol unit stopped at an intersection overnight.

According to the Houston Police Department, it happened just before 1 a.m. at the intersection of Airline Drive and Little York Road in northwest Houston.

The patrol unit was waiting for the light to change when a male driver in another vehicle rear-ended the car, police said.

The police officer was checked out by EMS and is expected to be OK, police said.

The suspect driver was taken into custody.