Fairfax County Police say John Jackson, a former sergeant with the department, and his daughter were found dead after an apparent homicide-suicide this morning.

According to police reports, the bodies of the 40-year-old man and his 13-year-old daughter, Alexis, were found by a family member inside an SUV parked in the driveway of a house on Forest Grove Drive in Annandale around 1 a.m. this morning. Police believe the deaths occurred between midnight and 1 a.m., and say the deceased lived on Summers Lane in Falls Church.

The investigation is ongoing, and a medical examiner will determine cause and manner of death.

Jackson was a former sergeant with the Fairfax County Police Department, having served for 16 years before leaving the department in June 2010.