The victims, a husband and wife in their 20s, were found dead in the front seats of their sport utility vehicle at around 12:45 p.m., according to Vacaville police.
Their car was parked outside an apartment complex where they lived, which is located in the 1100 block of Farmington Drive, police said.
There are no obvious signs of trauma or foul play, police said. Investigators searched their vehicle and apartment for leads today but could not definitively determine how they died.
Their vehicle was brought to the police department for inspection, in part to see if a mechanical malfunction was responsible for their deaths.
An autopsy is scheduled for early next week, according to the Solano County Coroner.
Vacaville Police Department detectives are working with detectives from the Office of Special Investigations at Travis Air Force Base.
Anyone with information about the deaths is asked to call Detective Otha Livingston at (707) 449-5270 or (707) 449-5200. Police are investigating the deaths of two Travis Air Force Base airmen whose bodies were found in their parked car this afternoon.
