Florida Murder Mystery: Jill Halliburton Su Found Dead in Bathtub
09/11/2014 AT 07:15 PM EDT
The wife of a prominent professor and a relative of the founders of the billion-dollar Halliburton oil empire, Su lived in an upscale mansion in a gated Florida community. In her spare time, she read to the blind and raised money for various charities.
But everything changed Monday when Su, 59, was found dead in a bizarre murder mystery that is raising more questions than answers.
"She was always involved in helping others. She was the first person to volunteer for anything," says her friend Theresa Randolph, who she has known for more than a decade. "Just a very sweet, kind, giving woman."
On Monday morning, Dr. Nan Yao Su, a professor of entomology at the University of Florida's Research and Education Center in Fort Lauderdale, tried to watch the live feed of his home's security cameras. When he was unable to see the feed, he called home. Receiving no answer, he called his adult son and asked him to check on the house.
When the son arrived at the waterfront mansion, he found a chilling scene. A glass door had been broken; shards of glass covered the ground. At least one room had been ransacked. And worst of all, his mother was lying dead in a bathtub.
The son called 911. "The initial call came in as a possible suicide," Davie Police Captain Dale Engle told ABC News, "but it became very evident that this was not a suicide, but in fact a homicide."
How, exactly, she died remains a mystery. Reached by PEOPLE, police wouldn't comment on either the cause or manner of death.
Both father and son were extensively questioned by police – and a police spokesman tells PEOPLE that they were both very cooperative and did not hire lawyers. At this point, neither are considered suspects, although police haven't ruled them out.
"I don't want to say that anybody's been ruled out as a suspect," Engle said. "At this time, this is a very active investigation."
Friends don't think that Dr. Nan Yao Su could possibly be involved. "Theirs was a strong marriage," Randolph tells PEOPLE. "I can't imagine that he had anything to do with it."
Police have searched the lake behind the family home and are asking neighbors to turn over their surveillance videos.
"This is a gated community. There's only one way in and out," Sgt. Edwin Smith, spokesman for the Davie Police Department, told reporters. "We would ask anybody in this neighborhood to contact us if they saw anything unusual."
The death has left her loved ones reeling. "Everyone is devastated, just devastated," Randolph says. "It's going to take a long time for this to sink in."