By CBS3 Staff

PHILADELPHIA (CBS) — Keith Gibson is the suspected gunman in the fatal shooting and robbery on June 5 of 41-year-old Dunkin’ manager Christine Lugo. Gibson was taken into custody on June 8.

Police say he was wanted for other robberies and deadly shootings, including the murder of his own mother in February.

Philadelphia homicide detectives tell Eyewitness News Reporter Joe Holden that they believe Gibson is a serial killer.

Police say Lugo was opening the Dunkin’ located on the 500 block of West Lehigh Avenue in Philadelphia’s Fairhill section just before 5:30 a.m. Saturday, June 5 when Gibson fatally shot her during a robbery.

Police say after the Dunkin’ shooting, he shot and critically wounded a 19-year-old in Wilmington and pistol-whipped a female worker at a Rite Aid in New Castle.

On Feb. 8, police say he killed his own mother at a location on Ridge Avenue and on May 15 officials say he killed a worker at a T-Mobile store in Elsmere, Delaware.

In 2008, he was convicted and served time for committing a homicide and commercial robbery in Delaware.

Wilmington police confirm Gibson was taken into custody on June 8 in connection with an armed robbery around 8:20 a.m. He was charged with first-degree robbery and is being held in Delaware.

When he was captured, police say he was wearing a bulletproof vest and was armed with a knife and loaded gun. A revolver that is preliminarily believed to be connected to many of the shootings was recovered.

On June 16, Gibson was officially charged with the murder of his own mother.