Niagara County Sheriff's officials say the three armed robberies in the Lockport area on Sunday may have been committed by the same suspect or group of people.
"We believe they're related," Undersheriff Michael Filicetti said Monday afternoon.
Filicetti said sheriff's investigators are working with the New York State Police following up leads.
In at least two of the robberies, clothing and the weapon displayed were recovered by police.
The three robberies occurred in the span of just under eight hours.
In the first incident, the NOCO gas station on S. Transit Road was robbed at knifepoint at 3:20 p.m. The suspect was wearing a jacket with a British Union symbol on the back and had a blue ski mask over his face. He was carrying a large kitchen knife. He took an undetermined amount of money and fled the business.
The mask, knife and jacket were later found by police behind the gas station.
The suspect hopped a fence into the Woodlands Manufactured Home complex, where witnesses saw the suspect enter a white sedan on Norwood Avenue. The car had been waiting for the suspect, and there may have been two other people in the car.
In the second incident, just after 6:30 p.m., Crosby's, 7953 Rochester Road in Gasport, was robbed by a suspect wearing a black ski mask with holes for the eyes and mouth cut out of it and a long tan jacket with a hood. The suspect displayed a knife and ran out of the store with $300.
He was seen walking toward the railroad tracks to the north of the store, the sheriff's office said. The knife, mask and tan jacket were all recovered by police near the south east corner of the store.
The third incident occurred just before 11 p.m. when a Sunoco gas station on the corner of South Transit and Robinson roads was robbed by a suspect with a knife. Sheriff's officials said the suspect is believed to have fled down Robinson Road.