DOVER, Del. (AP) — A suspected serial killer accused in the deaths of six people in Delaware and Pennsylvania in 2021 was convicted of murder and other crimes by a Delaware jury on Tuesday.

The jury deliberated for about six hours over two days before finding Keith Gibson of Philadelphia guilty of murder and robbery in the killings of Elsmere cellphone store clerk Leslie Ruiz-Basilio, 28, and Wilmington drug dealer Ronald Wright, 42.

Gibson, 41, also was convicted of attempted murder and robbery in the shooting of Wilmington store clerk Belal Almansoori, armed robbery of a drug store, assault, conspiracy, and gun crimes.

Gibson faces mandatory sentences of life in prison for the murder convictions. The judge did not immediately set a sentencing date.

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 have said they will pursue those charges after Gibson is prosecuted in Delaware.

Delaware prosecutors relied heavily on video surveillance footage showing the robberies and shootings of Ruiz-Basilio and Almansoori. They also argued that ballistics evidence linked the shootings of Ruiz-Basilio and Wright and tied them to a revolver recovered when Gibson was arrested.

Clothing and other evidence, including a bicycle belonging to Gibson found near the cellphone store, also pointed to Gibson as the gunman in each of the crimes, said prosecutors, who noted that a friend of Gibson identified him as the man seen in surveillance footage from the shooting scenes.

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 was no DNA or fingerprint evidence linking Gibson to the crimes.

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 and shoots her in the head at point-blank range as her arms are raised. He then walks out of the store with stolen cash and cellphones 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, lay on the floor of his store pretending to be dead after a gunman’s first shot missed him. After stealing several items, the gunman shot the prone teenager in the head. As he was leaving, the gunman turned and shot 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 said was a known “drug house.” Gibson was later found with a shoulder bag in which prosecutors said 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 that also was captured on surveillance video.

Gibson 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.

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 said was 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.