A Westchester county man serving probation for a gun charge was arrested for beating his 32-year-old ex-girlfriend to death in a fit of violence that lasted hours and only ended when he fled with the couple’s 2-year-old son, authorities said Wednesday.

Justin Bartley, 32, was arrested just hours after he allegedly left Roseberline Philippe dead inside a Days Inn motel in Elmsford, according to a lohud.com report.

Philippe met her child’s father at room 230 in the motel on Valley Road off the Saw Mill River Parkway around 8:30 a.m. Sunday following a confrontation a day prior at the victim’s West Chester home, where she lived with her parents, according to lohud.com.

It wasn’t until 4:30 p.m. that day that footage shows Bartley fleeing the motel with his son, court documents show. Cleaning staff would later find the Philippe’s body, lohud.com reported.

Philippe met her child's father at Room 230 in the motel located on Valley Road off the Saw Mill River Parkway around 8:30 a.m. Sunday following confrontation a day prior at the victim's West Chester home, where she lived with her parents, according to lohud. (Google)Philippe met her child’s father at Room 230 in the motel located on Valley Road off the Saw Mill River Parkway around 8:30 a.m. Sunday. (Google)

Bartley, who is on probation for a gun conviction in Rockland County, fled to the Bronx, where he left the child with relatives and was arrested later that day by a task force involving Elmsford and county police and the FBI.

A police investigation determined Bartley beat his ex for hours before she died, lohud.com reported.

“We thought she was coming home,” the victim’s sister, Yvena Philippe, told lohud.com. “But I think he had a plan for her not to come home.”

Philippe, an office assistant at White Plains Hospital, met Bartley at Port Chester High School and fell in love with him years later, only to come to fear him following the birth of their son, her sister said.

“She was so sweet and always laughing even if she was dealing with stuff,” Yvena Philippe told lohud.com “She was a giver and he took advantage of her in that way.”