PHILADELPHIA (CBS) — Police have arrested a man they are calling a serial killer. Keith Gibson is accused in the murder of a North Philadelphia Dunkin’ store manager and the manager of a Delaware cellphone store. Eyewitness News reporter Alicia Roberts spoke with family and friends of the victims.

Late Tuesday night, Wilmington police confirmed Gibson was taken into custody today in connection with an armed robbery around 8:20 Tuesday morning. He was wearing a bulletproof vest and was armed with a knife and loaded gun.

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He’s charged with first-degree robbery and is being held in Delaware.

News that Gibson may be connected to the death of at least two other women didn’t come as a complete surprise to those grieving for the victims.

As news spread of the robbery and cold-blood killing of North Philadelphia Dunkin’ store manager Christine Lugo on Saturday morning, many couldn’t overlook the similarities of the May 15 robbery and shooting death of Elsmere, Delaware Metro PCS manager Leslie Lizet Basilio.

“I don’t believe in coincidences,” said Luis Bernabe, a cousin of Basilio.

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And the man seen at the scene in surveillance images at the time of both murders …”He definitely knew what he was doing. This was something that he seemed like he did before and he was just very calm and cool about it,” Dunkin’ security guard Michael Bahm said.

As Pennsylvania and Delaware officials continue to piece together details in the two cases and potentially others, questions now remain as to why both women were alone in their stores.

“The overnight person had called out, and so she had come in earlier than the rest of the crew just to bake and do little things in the store,” Bahm said.

Could this potential serial killer have been stopped sooner?

“It would bring some closure. It would just open a new door of why, could it have been prevented?” Bernabe said.

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CBS3’s Alicia Roberts reports.