FAIRFAX COUNTY, Va. (DC News Now) — Nearly seven months after a deadly shooting at a family’s home in the Reston area, detectives said they arrested the family’s au pair for murder.

The Fairfax County Police Department (FCPD) said Thursday that the charge against Juliana Peres Magalhaes, 23, of Reston was in connection to the killing of Joseph Ryan, 39, of Springfield, inside the home where she lived with the family for which she worked.

Officers found Ryan shot inside the home of Christine Banfield, 37, on Feb. 24. He died there. They found Banfield stabbed in an upstairs bedroom near Ryan. Banfield died at the hospital as a result of the stabbing.

Lt. Erin Weeks of the Fairfax County Police Department Major Crimes Bureau said Thursday that the investigation revealed that Banfield and Ryan knew each other prior to the shooting, but could not say whether Peres Magalhaes knew Ryan.

During the original 911 call made that morning, Brendan Banfield, a special agent for the IRS, told operators that he’d shot a man who had stabbed his wife. On Thursday, police said that Brendan Banfield had been outside the home at the time of the shooting.

Neighbors tell DC News Now that up until her arrest last week, Peres Magalhaes was still seen working for the family and caring for the couple’s child. It is unclear whether she was still working in her capacity as an au pair. Several neighbors said it was shocking to see officers appear and take Peres Magalhaes into custody as she walked from the school bus stop the morning of her arrest.

Investigators are still working to learn who killed Christine Banfield as of Thursday.

Investigators described the scene as “horrific.” Christine Banfield had been stabbed in the upper body multiple times. Ryan had been shot in the upper body multiple times.

A 4-year-old child was inside the home at the time of the incident.

A lot of unanswered questions and a continuous police presence on Stable Brook Way after what unfolded on Friday as police try to piece together the complicated scene of two killings.

As of Thursday, detectives said they still were interviewing people and looking at evidence to determine whether anyone else should face charges in the case.

Police said the charge against Peres Magalhaes in connection to Ryan’s death is second degree murder. She is being held at the Fairfax County Adult Detention Center.