CPD said two to four men, ages 18 to 25, have approached victims near their cars, threatening them with guns and demanding property.
A silver Mercedes was taken in one of the robberies. It was seen in two thefts that happened later.
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Two robberies were Sunday night. Another was Monday.
They took place at 7:55 p.m. Sunday in the 200-block of North Carpenter Street, 10:35 p.m. Sunday in the 900-block of West 19th Street and just after 6:45 p.m. Monday in the 3500-block of West Henderson Street.
Anyone with information should call Area Three detectives at 312-744-8263.