A man has been sentenced to 20 years in prison in a nearly 30-year-old murder case in Galveston County.

Clyde Hedrick, 61, was convicted of involuntary manslaughter in the death of Ellen Rae Beason on Friday.

Investigators first ruled her death as undetermined, and Hedrick was convicted of abuse of a corpse in 1986.

New forensic evidence showed Beason died from a blow to the back of the head.

Hedrick pleaded not guilty to murder.

Hedrick's defense attorney argued that Beason drowned while the pair was skinny dipping. Hedrick said he panicked and didn't think anyone would believe him, so he put her body under a discarded couch on the Galveston Causeway.

Prosecutors said Beason's head was bashed in and Hedrick hid her body to cover his crime.

When deciding guilt or innocence, jurors had the option of finding Hedrick guilty or innocent of murder, guilty or innocent of involuntary manslaughter or guilty or innocent of criminally negligent homicide.

Hedrick was sentenced Monday to 20 years in prison.