WILMINGTON, Del. (AP) — A Delaware jury heard closing arguments and began deliberations Monday in the trial of a suspected serial killer accused in the deaths of six people in Delaware and Pennsylvania in 2021.

Keith Gibson, 41, of Philadelphia, is charged with murder in the killings of Elsmere cellphone store clerk Leslie Ruiz-Basilio, 28, and Wilmington drug dealer Ronald Wright, 42, during separate robberies. He is also charged with attempted murder in the shooting of Wilmington store clerk Belal Almansoori, and the armed robbery of a drug store.

The Philadelphia district attorney, meanwhile, has approved murder charges against Gibson in the killings of his mother and a Philadelphia doughnut shop manager, as well as the deaths of two men found shot in the head at a store in Philadelphia’s Germantown neighborhood. Authorities say they will pursue those charges after Gibson is prosecuted in Delaware.

Prosecutors in Delaware have relied heavily on video surveillance footage showing the robberies and shootings of Ruiz-Basilio and Almansoori. They also argue that ballistics evidence links the shootings of Ruiz-Basilio and Wright and ties them to a revolver recovered when Gibson was arrested.

Surveillance footage from May 15, 2021, at the Metro PCS store in Elsmere shows Ruiz-Basilio being confronted by a gunman, who takes her to the back of the store. As Ruiz-Basilio has her arms raised, the gunman raises his weapon and shoots her in the head at point-blank range. He then walks out of the store with stolen cash and cell phones and drives away in her SUV. The stolen vehicle was later recovered in Philadelphia near Gibson’s home.

Almansoori, who was shot on June 6, 2021, is seen lying on the floor of his store pretending to be dead after a gunman’s first shot missed him. After stealing several items, the gunman shoots the prone teenager in the head. As he leaves, the gunman turns and shoots Almansoori again. Almansoori survived and testified in Gibson’s trial.

Almansoori was shot one day after Wright was killed in his Wilmington residence, which prosecutors say was a known “drug house.” Gibson was later found with a shoulder bag in which prosecutors say Wright kept his drugs.

Earlier on the same day Wright was shot, Christine Lugo, 40, was confronted by a gunman as she opened a Dunkin’ shop in north Philadelphia. Police say Gibson pushed her inside, took about $300 and shot her in the head, a killing also captured on surveillance video.

Prosecutors say the videos, ballistics, clothing and other evidence, including a bicycle belonging to Gibson found near the cellphone store, are “pieces of a puzzle” that shows “a clear picture” of Gibson as the “gloved up, masked up” gunman in each of the crimes. They also note that Amanda Masteller, a friend of Gibson, identified him as the man seen in surveillance footage from the shooting scenes.

“You have all these commonalities,” prosecutor John Downs told jurors.

Defense attorneys presented no evidence of their own and did not call any witnesses. Instead, they tried to poke holes in the prosecution’s case by cross-examining witnesses and pointing out that there is no DNA or fingerprint evidence linking Gibson to the crimes.

“There are a lot of missing pieces to this puzzle,” defense attorney Megan Davies told jurors Monday. “These missing pieces are reasonable doubt.”

Gibson, who calls himself “the Beast,” is accused of going on a violent rampage shortly after being released in December 2020 from a Delaware prison where he served about 13 years for manslaughter and possession of a firearm during the commission of a felony. After the cellphone store robbery, authorities arrested a man with one of the stolen phones. Data stored on the device included Gibson’s phone number and a contact named “Beast.”

Gibson was arrested on June 8, 2021, after the robbery of a Wilmington Rite Aid store, during which a clerk gave him a bundle of cash containing a GPS tracking device. When police arrested him, Gibson was wearing body armor and carrying unique ammunition that prosecutors say is consistent with bullet fragments found at the two murder scenes. A revolver that prosecutors say was used in the shootings was found hidden near the spot where police arrested Gibson.