FORT WORTH -- A mistrial was declared in the wrongful-death suit against Texas millionaire T. Cullen Davis after jurors said they could not agree on whether he shot four people at his mansion 11 years ago.

The mistrial came in the fourth day of deliberations and perpetuated one of the state's most famous murder mysteries, which has fascinated Texans for more than a decade.

Cullen Davis had faced two criminal trials in the shooting. The first ended in a mistrial during jury selection, and an Amarillo jury acquitted him in the second in 1977.

State District Court Judge Claude Williams declared the mistrial in the civil suit after reopening arguments earlier in the day in an attempt to break an 8-to-4 jury deadlock, reportedly in the favor of the plaintiffs. A 10-to-2 verdict is needed in civil trials.

Jurors said they could not agree whether Davis should have to pay the $16.5 million in damages sought by his ex-wife, Priscilla Davis, and her ex-husband, Jack Wilborn, for the death of their daughter, Andrea, 12.

According to eyewitness testimony, a black-clad gunman killed the child and Priscilla Davis' boyfriend, Stan Farr, 30, on Aug. 2, 1976. Priscilla Davis and a friend were wounded.