UPDATE: Father Of Man Charged In Quadruple Slaying Was Killed Day Before

CHICAGO (CBS) — A 19-year-old man has been charged with murder in the slayings of four men at a restaurant in the South Shore neighborhood last week.

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Police said Maurice Harris was arrested Tuesday afternoon and charged with four counts of first-degree murder in connection with the Thursday shooting deaths of four men at Nadia Fish & Chicken, on the 2700 block of East 75th Street.

The shooting happened around 4 p.m. Thursday, when a man walked up to the restaurant and opened fire.

Once police arrived, two men – 28-year-old Emmanuel Stokes and 32-year-old Edwin Davis – were found dead inside the restaurant. Two brothers – 20-year-old Dillon Jackson and 19-year-old Raheem Jackson, were found dead outside the restaurant.

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Police said the attack was believed to be gang-related retaliation for an earlier fatal shooting.

The Jackson brothers were visiting their mother, an employee of the restaurant.

The fatal shooting was part of a bloody day in the South Shore neighborhood. Earlier Thursday, police found a pregnant woman fatally shot in an apartment. That night, two more people were fatally shot in an incident Police Supt. Eddie Johnson said may have been connected to the four deaths. He said those two incidents appeared to be gang-related.

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Police were scheduled to discuss details of the quadruple homicide at a Wednesday morning press conference at Chicago Police Headquarters.