SEWICKLEY TOWNSHIP (KDKA) — Police say a known heroin user, who is accused of using a syringe to puncture the feet of his girlfriend’s son, has been taken into custody.

Police said Salvatore Salvio turned himself in on Saturday in Belle Vernon.

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He is facing assault charges, accused of beating and injuring his girlfriend’s 1-year-old child.

Police say when Salvio’s girlfriend came home Wednesday to Church Street in Sewickley Township, she found her son crying upstairs.

He had bruising, swelling and facial injuries, along with puncture marks to both of his feet.

Police say Salvio “is a heroin user,” and they say the puncture mark injuries on the child’s feet may be from a syringe.

The mother told investigators when she left for work “her child had no injuries and was acting completely normally.”

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According to the criminal complaint, she left the child in the care of her boyfriend while she was at work from 11:30 a.m. to 5:30 p.m. He is identified by police as Salvio.

Police say the girlfriend confronted Salvio about the injuries, but he denied injuring the boy.

When she tried to leave the home with her son, police say Salvio “threatened to knock her out.”

She was eventually able to make it to a neighbor’s home, where she called for help.

Salvio took her cell phone and drove off in her car before police arrived.

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Stay with KDKA for more on this developing story.