WILLINGBORO — A 23-year-old man accused of killing a grandmother and child before kidnapping his ex-girlfriend last week now has been tied to a separate murder this past winter, according to the Burlington County Prosecutor's Office.

Terrence Matthews gunned down 21-year-old Davell Williamson, also of Willingboro, and another man on Feb. 18 just before 1 a.m. as they sat in a car on Millbrook Lane, Burlington County Prosecutor Scott Coffina said.

Williamson was pronounced dead at a local hospital, while his passenger was treated for a gunshot wound in the arm.

The additional count of murder, as well as Unlawful Possession of a Weapon, Possession of a Weapon for an Unlawful Purpose and Certain Persons Not to Possess Firearms were filed Saturday evening.

Matthews will be scheduled for a first appearance in Superior Court in Mount Holly.

He has been in Burlington County Jail, since being arrested on Thursday for the murders of 68-year-old Jennifer Vassell and 9-year-old Ishon Mathiln Jr.

The victims were the grandmother and younger brother of Matthews' ex-girlfriend, 22-year-old Krissida Williams, who was at work on Wednesday evening when the attack on her family happened, according to Coffina.

Police said both victims had been stabbed repeatedly, and the child also appeared to have been drowned in a bathtub.

Williams said when she returned to the home they all shared that night, Matthews held her against her will until the next morning when he took her to a Wawa store in Westhampton. There, an employee called police after Williams told a clerk that Matthews had killed her family.

Camden County police arrested Matthews after a high-speed chase that Matthews streamed on Facebook live. The pursuit ended when Matthews crashed his Toyota Scion into a utility pole.

6ABC Action News shared a portion of the live stream, showing a shirtless Matthews behind the wheel of his car with police not far behind.

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