His demeanor was far from the calm, "matter-of-fact cop" on the beat.
In fact, witnesses described the man flashing a star-shaped badge as "agitated" -- actually yelling at two drivers he confronted.
The only problem is, this guy was no cop. He was a police impersonator, real cops on Nassau say.
Twice Sunday night -- first in Baldwin and then in East Meadow -- the bogus cop displayed that badge. In Baldwin, his car had struck another. An hour and a half later in East Meadow, the phony officer actually pulled over a driver for no apparent reason.
"What his motive behind this is, we don't know," said Nassau police Detective Sgt. Anthony Repalone. "But we believe it was the same guy in both cases."
No one was hurt because both drivers became suspicious of the man with the badge.
After his car was struck and the badge was shoved in his face, the first driver ran from his vehicle to a nearby fire house.
The second driver, who had been pulled over, actually shifted his car into reverse and drove away from the fake officer, calling 911 for help.
Police are now working with the witnesses on a sketch of the cop impersonator, who is described as a white male, in his 30s, sporting a crew cut and driving a late model white or cream-colored Mitsubishi Gallant.
"It's scary and unsafe," said one driver from Uniondale.
"There's a lot of people in this world with problems," added driver Pat Sjursen. "If he gets his kicks doing something like this, he will keep doing it until he gets caught."
There have been 14 police impersonator cases so far this year in Nassau County, Sgt. Repalone added -- an increase over the same time period in 2009.
If you are stopped and question whether the cop is real, police urge that you stay in your car and call 911 immediately.