Police in Oak Park are trying to stop a rash of robberies that has hit the suburb over the past month.
Investigators say there were four robberies in the month of July, and there seems to be a pattern.
The most recent robberies occurred on this past Tuesday at Austin Boulevard and LeMoyne Parkway, on the boundary line with Chicago's North Austin neighborhood.
In those incidents, three African-American males of similar descriptions — one armed with a semi-automatic handgun — surrounded their victims and took wallets and other valuables.
Neither victim was injured.
But in two earlier armed robberies, on July 10 and July 20, the victims were battered and injured, one severely.
Those robberies were on the 400 block of Wisconsin Avenue at 3 a.m. and the 100 block of Washington Boulevard at 2:20 a.m.
"There appears to be a pattern emerging," Detective Cmdr. Ladon Reynolds said.
"We're in the process of acquiring information from Chicago Police to see if they're reporting any similar issues."
Reynolds said the offender descriptions don't match all four incidents, but said three offenders were in each case, and a black or dark semi-automatic handgun used in each.
In three of the four incidents, the robberies occurred very late at night.
A Cicero man riding his bike on the 1500 block of North Austin Boulevard was surrounded by three men at 1:15 a.m. this past Tuesday.
One offender, described as 19-years old, 6 feet 2 inches tall, thin build and black hair in braids, pointed a gun at the victim and demanded his bike, wallet and cell phone.
A second robber, described as 19, 5 feet 7 inches tall, 150 pounds and short black hair, grabbed the bike from the man and rode off.
The third man, described as 25, 6 feet 1 inch tall with a light complexion and a small afro, ran off with the gunman.
That afternoon at 5:55 p.m., a Chicago man walking on the first block of LeMoyne Parkway in Oak Park, was surrounded by three black males, one of whom pointed a large black semi-automatic handgun at him.
Another man placed a sharp object against the victim's back and went through his pockets, stealing his wallet, which contained $300 cash. The gunman then took the cash from the wallet and threw the wallet in the man's face before running off.