Windsor police are looking for a suspect believed to be responsible for three armed robberies in as many days.
They say the first one happened Friday morning at a convenience store and the other two happened minutes apart Sunday night at another convenience store and a sub shop.
In all three cases, the suspect was described as being armed with a black handgun and his face covered.
Police say a man witnessed the suspect running away from one of the robberies on Sunday night but he did not remain at the scene to speak to officers.
Investigators are asking the man, described as being about 50 years old, to contact them.
Police are also checking to see if the same suspect could be responsible for two armed robberies in Sarnia earlier this month.
Sgt. Brett Corey of Windsor police says so far, no one has been hurt.
"There is no violence being threatened, he is pointing the gun but he is very calm and we are asking clerks to be calm themselves," Sgt. Corey said.