A gunman who fatally shot a Chicago police officer’s son and wounded his friend last summer mistook them for rival gang members, police officials said Friday in announcing a break in the investigation.
Arshell “Trey” Dennis III, who was about to start his junior year studying journalism at St. John’s University in New York City, had returned to his Southwest Side home for a few days last August to visit his parents at their Wrightwood neighborhood residence.
Police said Anthony Moore, 18, has been charged as the gunman who killed the 19-year-old and wounded his 20-year-old friend on the Dennis family’s front porch in the 2900 block of West 82nd Street about 12:05 a.m. on Aug. 14. A third friend was uninjured.
Moore, of the 7900 block of South Sawyer Avenue, was already in custody on a charge of possession of a stolen motor vehicle when officials charged him in Dennis’ murder.
Cmdr. Brendan Deenihan, who supervised the Area Central detectives investigating the shooting, said Moore had picked up six arrests in the three months after he turned 18 in November.
Dennis’ father, police Sgt. Arshell “Chico” Dennis II, attended the news conference announcing the charges, but he declined to comment to reporters. In a soft-spoken voice, he could be heard thanking detectives who had been working on his son’s murder over the past nine months.
“Every officer in this department took his murder personally,” said a teary-eyed Superintendent Eddie Johnson, who worked years ago with the elder Dennis in the South Side’s Gresham patrol district when both were patrol officers. “And we vowed not to stop until we found his killer.”
Deenihan told reporters that Moore wrongly assumed that the younger Dennis and his two friends were members of an opposing gang when he opened fire on them.
Deenihan said neither Dennis nor his two friends were in or affiliated with gangs.
Deenihan said Moore and at least one other suspect were parking some stolen vehicles nearby before emerging from a gangway and opening fire on Dennis and his friends.
Moore “basically saw three male blacks in their late teens or early 20s sitting on a porch, and they decided this was an opposing gang and … decided to shoot these individuals,” Deenihan said.
After the shooting, Moore and at least one other suspect fled the scene in the stolen vehicles, Deenihan said.
Detectives need to investigate further before any additional charges might be brought, Deenihan said.
Deenihan said Moore was “bragging to friends” and “speaking to other individuals” about “killing an opposing gang member.”
Detectives also reviewed video evidence that helped them make the arrest, Deenihan said.
Dennis was shot in the chest and pronounced dead less than an hour later at Little Company of Mary Hospital in Evergreen Park. His one friend sustained wounds to his arm and side of his body and was treated at Advocate Christ Medical Center in Oak Lawn.
Dennis was among the more than 760 homicide victims of Chicago’s most violent year in two decades.
He had been in Chicago for three days to see his mother, who was ill, and planned to return to New York on that Sunday afternoon, but the shooting happened hours earlier that day.
Johnson said he knows there is nothing the department could do to make up for what happened.
“But I hope this will help bring some sort of peace and closure to the family,” Johnson said as he turned to his left and looked at the elder Dennis.