The victims, police say, are often coming home late from the train stations.
Commuters coming home to Pelham, three in the late night hours, have come face to face with a dangerous thief.
It is prompting a warning and a reward in hopes he can be stopped.
"Maybe at midnight he was robbed at gunpoint, about a quarter mile from the train station on the walk home," said Conall Chabrunn, a Pelham resident.
Conall Chabrunn's friend, he says, was left shaken but not injured by the robbery.
And now in his neighborhood he hears another man was robbed last Wednesday at Elderwood and Second Street East.
"You get a gun pointed at you face it obviously is not like any joke, it's pretty serious stuff," Chabrunn said.
Police believe as he walked along the sidewalk, turning onto Elderwood, the victim was confronted by the thief who was armed with a semi automatic weapon.
Neighbors say they heard a faint conversation but nothing to alarm them to the theft of money and personal items right under this street lamp.
"The robberies before this were Tuesday and Thursday. This was our first Wednesday one. But the same MO. The same type by the train station or people walking home from the train station," said Detective John Hynes, Pelham Police Department.
The first robbery, Chabrunn's friend, occurred on First Street in early January.
A second person was robbed January 31st in the 200 block of Monterey Avenue and the third was just last week 10 blocks from the station.
"We're all certainly very concerned. We are supportive of the police that they are working, doing their jobs. And we're certainly trying to be smart about our own behavior," said Fiona Watt, a Pelham resident.
In addition to Pelham, investigators think the same suspect pulled off similar robberies in Harrison, both the village and Town of Mamaroneck and New Rochelle.
A brief description of the suspect is of a black male 5'10" to 6' tall, 175 to 200 pounds.
He dressed in black and pulled out a black handgun.
"With the gun that adds more danger into it. We are very concerned obviously all police departments would be concerned with something like this," Det. Hynes said.
Police also stress that you should not resist and give up the property if confronted.
"It's scary to know that this happened. Especially if, I'm going to school and I come back and you are by yourself just wanting to go to your house. It's very scary," said Alejandra Adarve, a student.
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