The district attorney's office said Carly Stevenson, 26, of Hatboro, was arrested in connection with the death of 19-year-old Brandon Cron.
Back on September 29th, police say they were called to an apartment in the 100 block of North York Road for a report of an unresponsive person.
Stevenson allegedly told police that Cron, her boyfriend, had blue lips, was cold to the touch and was not breathing.
Medics said Cron was dead at the scene.
Investigators say Stevenson gave Cron the heroin the day before and, after he died, allegedly tried to get rid of the evidence.
That evidence, syringes and blue wax paper bags, were found in a trash can outside the apartment, police said.
Cron died from "an adverse reaction to heroin," according to investigators.
District Attorney Risa Vetri Ferman said Stevenson was arrested on Tuesday and was charged under the "Drug Delivery Resulting in Death" statute.
Stevenson faces up to 40 years in prison if convicted.
She is being held on $100,000 bail.