Police in southeast Missouri say black-box data from a car found in the Mississippi River with a body in the back seat is inconclusive.

An autopsy showed that 62-year-old Autumn Vinson, of Jackson, drowned when her car went into the river at Cape Girardeau on Jan. 17.

But the Southeast Missourian reports investigators still don't know how or why the vehicle went into water.

Crews pulled the submerged car from 5 to 6 feet of water, and investigators removed a black box that records information about the vehicle's movements. But after drying the box to remove moisture, police said, the device didn't show anything about an abrupt acceleration or deceleration.

Investigators believe the device's prolonged submersion could have affected its reliability.

Toxicology reports on Vinson are still pending.