A 14-year-old Maryland girl and her 19-year-old boyfriend were arrested and accused of conspiring to kill her father, a popular local blogger and podcaster.

WJZ-TV reported on Sunday that police believe the girl Morgan Arnold, left a screen door open in her home in Ellicott City, Maryland, allowing Jason Bulmer to enter early Friday morning. She then allegedly encouraged Bulmer to stab her father, Dennis Lane. Another woman in the home at the time called police, who said they arrived to find Bulmer there with blood on his hands and clothes.

Authorities did not identify a motive, but said the two had been planning the fatal attack for weeks, and that Lane had promised Bulmer that she would "run away" with him afterward. The suspects are charged with first-degree murder and conspiracy to commit murder.

"It's our detectives' understanding that the two have conspired over the last two months, exchanging electronic communication about planning to kill Mr. Lane," a police spokesperson told the station.

The Baltimore Sun reported on Monday that the suspects were held without bail over the weekend and are scheduled for a bail review hearing on Monday. Their school, Mount Hebron High, is bringing counselors and psychologists on campus to help students deal with the incident.

Arnold's mother, Cindi Arnold, refused to comment.

Watch WJZ's report on Lane's death, aired Monday, below.