The New York City Police Department Hate Crimes Bureau is investigating a possible bias-attack spree in Manhattan.
Investigators say the latest attack happened outside an Upper East Side apartment building early Saturday morning.
The victim, 36-year-old Joseph Holladay, says he was in town for the gay pride parade and was approached by a group of men using anti-gay slurs while smoking a cigarette outside his friend's apartment on East 85th Street.
Police say one of the attackers hit Holladay in the head with a gun and robbed him.
"We have three incidents that we're linking together, we see a pattern," said Police Commissioner Ray Kelly. "There was an incident in Carl Shurz Park that we believe he may be associated with two other events -- one that happened Saturday morning, the other happened Sunday morning. All of these events happened on the Upper East Side, the 19th precinct."
"I found a notice under my door saying there was an attack by a group. I didn't realize it was in front of the building," said one Upper East Side resident.
Police say the two other attacks took place May 31st, also on the Upper East Side.
They say two 19-year-old men were robbed and beaten by four suspects.
NYPD investigators say they're looking at six similar crimes that could be linked.
Police say one of the suspects is described as being between 20 to 22 years old, about six feet tall, and 170 pounds.
Anyone with information about the case is being asked to contact Crime Stoppers by calling 1-800-577-TIPS, by texting TIP577 to CRIMES, or by going to NYPDCrimeStoppers.com.