Police think a man who robbed a northwest suburban store early Friday may have struck before, twice, at the same spot.

About 4:59 a.m., the suspect entered a store at 555 W. Devon Ave., pulled out a knife and demanded money, according to Park Ridge police.

The burglar, who had his face covered, was wearing a gray hooded sweatshirt and blue jeans, police said.

He is believed to be the same man who committed armed robberies at the same location on two previous occasions, police said.

Anyone with information should call Detective Hahn at (847) 318-6233.