Thursday, January 22, 7:05 p.m.

As a woman victim got off the Metra at the East 63rd Street station, a male offender approached her from behind with a knife and demanded her money. The victim began to scream as she ran away from the offender and called 911 on her cell phone. The offender ran. He is described as black, in his 20s, six feet tall, and of stocky build.

Friday, January 23, 8:30 p.m.

A man was walking along the 4700 block of South Ellis Avenue when two male offenders came up behind him and displayed a handgun. They demanded the man’s money and coat, which he surrendered. The offenders then took off in opposite directions. They are described as black, in their 20s, 6 foot 2, and were last seen wearing black ski masks.

Sunday, January 25, 5:35 p.m.

A male offender surprised a woman from behind after she got off a bus on East 49th Street and South Lake Park Drive, pointed a handgun at her, and demanded her purse. After the victim surrendered her purse, she was told to run back towards the bus stop. The offender is described as black, 15 to 19 years old, 5 foot 9, and 140 pounds, and was last seen with a yellow bandanna covering part of his face.