CHICAGO (CBS) — Police believe the murder of four people at a restaurant in the South Shore neighborhood last week was related to the shooting death of the suspect’s father one day earlier.

Maurice Harris, 19, has been charged with four counts of first-degree murder in the March 30 slayings of four men at Nadia Fish & Chicken, at 75th and Coles, police said.

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Area Central Detectives Cmdr. Brendan Deenihan said Harris is the son of 37-year-old Jerry Jacobs, who was slain on March 29. Police have said Jacobs was walking on the sidewalk at 79th and Phillips when four men got out of a vehicle and shot him.

Deenihan said “several witnesses’ identified Harris as the gunman in the quadruple homicide the day after his father was killed. Harris was arrested Tuesday near 127th and Western.

Police said Harris did not confess to the killings at 75th and Coles, so detectives don’t know the motive for that shooting, but he said it’s reasonable to believe the slayings were connected to Jacobs’ murder.

“It’s a reasonable belief that Jerry Jacobs is murdered, then 24 hours later his own son goes and kills four people. So, obviously, those two incidents are related,” Deenihan said.

Deenihan said he doesn’t know if Harris picked his victims at random, or if he believed they were involved in his father’s death.

“The offender in this incident invoked his rights, and didn’t give a confession, so that will come out at trial,” he said. “He chose to shoot all four people, so what was going through his head, who he actually was targeting, one versus two versus three versus four, but he definitely obviously shot all four of these individuals and killed all four.”

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Deenihan said all but one person involved in that shooting had gang affiliations.

Police Supt. Eddie Johnson said this is the first time Harris has been arrested as an adult, but he has an extensive juvenile record.

“He is no stranger to CPD, nor is he unfamiliar with using an illegal handgun,” Johnson said.

According to police, Jacobs had 47 arrests, including two for murder.

Deenihan said detectives believe the quadruple homicide also might be connected to a double murder later in the day less than a mile away.

Around 11 p.m., a man and a woman were passengers in a grey van headed south on South Shore Drive, when a black Jeep pulled up alongside them near 71st STreet, and someone inside opened fire, causing the van to crash into a pole.

“We have a belief that that incident may be related to this, as well, but I don’t want to go into details, due to the fact that we’re openly investigating that at this time,” Deenihan said.

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A pregnant woman also was slain earlier in the day of the quadruple slaying in a separate shooting in the South Shore neighborhood, but police said they do not believe that case is related to the other two fatal shootings that day. Police said 26-year-old Patrice Calvin – four months pregnant – had been shot in the head, and a source told CBS 2 the shooting might have been domestic-related.