The man suspected of fatally shooting the manager of a Dunkin’ doughnuts store during a robbery in Fairhill on Saturday is also a person of interest in at least five other homicides in Pennsylvania and Delaware, police said Wednesday.

Keith Gibson, 39 — who was arrested in Wilmington on Tuesday — was expected to be charged in the murder of Christine Lugo, 40, Chief Inspector Frank Vanore said Wednesday at a virtual news conference. Police said Lugo was shot in the head inside the Dunkin’ she managed on the 500 block of Lehigh Avenue after she gave Gibson $300 while being threatened at gunpoint.

In addition to that crime, Vanore said, detectives in Philadelphia and Delaware were investigating Gibson’s possible links to several other killings: Two men found shot to death in a North Philadelphia store in January, the slaying of Gibson’s mother at her East Falls workplace in February, the robbery and fatal shooting of an employee at a cellphone store in Elsmere, Del., last month, and the killing of a man during a street robbery in Delaware early Sunday.

Vanore said Gibson — who was paroled in 2020 after being imprisoned for a previous killing in Delaware — was also suspected of committing two robberies there before he was arrested Tuesday.

One occurred Sunday night — hours after the fatal street robbery — when authorities believe Gibson shot a convenience-store clerk during a robbery, leaving the man in “extremely critical condition,” Vanore said.

Then, on Tuesday morning, police say Gibson robbed a Wilmington Rite-Aid at gunpoint. Responding officers found Gibson a block away wearing a bulletproof vest, police said. He was taken into custody and charged with robbery and related crimes and was being held on $305,000 bail.

The alleged crime spree, jarring in its scope and violence, remained in the early stages of investigation Wednesday, Vanore said. Investigators were seeking to link evidence from each of the crime scenes, and ballistics tests were being conducted on a .357 revolver that police believe Gibson used in several of his alleged crimes.

“All of this is very active,” Vanore said.

Jane Roh, spokesperson for the Philadelphia District Attorney’s Office, said an arrest warrant had been approved Wednesday to charge Gibson with murder in Lugo’s slaying. Additional charges in other cases were “likely,” pending the outcome of forensics tests, Roh said. It was not clear when Gibson might be extradited to Philadelphia.

Vanore said Philadelphia police began investigating Gibson earlier this year for the fatal shooting of his mother, Christine, 54, a mental health counselor found shot to death inside her company’s offices Feb. 8.

Relatives and neighbors told police to investigate her son, Vanore said, but detectives found little evidence linking him — or anyone else — to the crime, even as they continued interviewing potential witnesses into May.

At one point, Vanore said, police took Gibson into custody and transported him to Delaware, because his mother’s neighbors had seen him in Philadelphia, which was a violation of his parole. But “at that point, we could not link him to the murder,” Vanore said, adding that Gibson was released from custody in Delaware in March.

A spokesperson for the Delaware Department of Corrections did not respond to a request for comment Wednesday on the status of Gibson’s supervision, or whether the agency knew of his potential link to a homicide.

In May, Leslie Lizet Basilio — a 28-year-old manager of a MetroPCS store in Elsmere — was shot dead during a robbery inside the store. Police there released photos of the suspect and said the gunman stole Basilio’s 2008 Cadillac Escalade, but the crime remained unsolved.

Then, on Saturday, Lugo was fatally shot as she began her shift at the Fairhill Dunkin’ around 5:30 a.m. Surveillance video showed Lugo complying with the gunman’s demands before she was killed. The homicide devastated her relatives and friends, many of whom have since left candles and notes of remembrance outside the store.

Vanore said that when police publicly released portions of the footage over the weekend, “one of the first calls we received was from Elsmere,” where police said the suspect and circumstances of the Dunkin’ killing seemed to match the robbery and homicide at the MetroPCS.

“We began working very closely with Delaware,” Vanore said, “knowing that we could possible have a pattern of behavior here.”

Still, Gibson remained on the lam. Police now believe he went on to commit the robbery and fatal shooting of a man on the street at 2:25 a.m. Sunday; the robbery and shooting of a convenience-store clerk at 9:15 p.m. Sunday; and the armed robbery of a Wilmington Rite Aid around 8:30 a.m. Tuesday.

Vanore did not provide additional details about those cases, and authorities in Wilmington did not respond to inquiries or declined to comment.

Vanore said Philadelphia police are now exploring whether Gibson was involved in other crimes, including a double homicide in January in North Philadelphia in which two men were found dead in the back of the Al-Madinah Traders store on the 3600 block of Germantown Avenue.

That murder was “kind of similar to some of the other cases we’ve seen both in Delaware and Philadelphia,” Vanore said, though he declined to offer many specifics. “It’s certainly on our list of cases we’re looking at,” he said.