At a news conference Thursday in Davie, Florida, police named Dayont'e Omar Resiles as a suspect in the 59-year-old woman's death. He is being charged with first-degree murder, according to police.
It was the first major development in the case since Su's body was found in her bathtub on Sept. 8.
Although the investigation seemed painfully slow to the South Florida community, authorities maintain that they were conducting a thorough investigation – even if they didn't talk about it publicly.
"There's a lot of information that we're keeping tight to our chest," Dale Engle, captain of the Davie Police Department, tells PEOPLE. "There is a lot of information that only one other person would know, and we don't want to share that right yet."
Su's death was discovered when her husband, Nan Yao, was unable to watch the live feeds of his home security camera. He called his son, Justin, and asked him to check on the house. When Justin arrived at the family home, he found her dead in the bathtub. A glass door had been shattered, and at least one room of the house had been ransacked.
The death was classified as a homicide. Police interviewed the family members and searched the canal behind the family home for evidence pertaining to the case.
Two neighbors tell PEOPLE that police asked for any surveillance video from their homes – a fact that Capt. Engle confirms.
"We have many detectives actively working this case," he says. "We're looking at surveillance videos and interviewing witnesses. We're definitely working very hard to get answers."
A Kind, Generous WomanAs the investigation continues, friends of Su are remembering the witty, kind woman with a quick wit and a self-depreciating sense of humor. She had logged more than 1,000 volunteer hours at Insight for the Blind, recording audio versions of periodicals. She approached her volunteer work with diligence and humor.
"She really cracked me up," says Matt Corey, president of Insight for the Blind, where Su had volunteered since 2005. "She was very quick on her feet, and was just a warm, kind woman."
According to those who knew her, she would sometimes talk about her husband, Nan Yao Su, a leading entomologist at the University of Florida.
"She was very proud of him," says Corey. "He's very accomplished."
Adds friend Theresa Randolph: "She almost never bragged, but when she did, it was about her family. She was devoted to being a wife and a mother."
One thing she didn't do: throw around her famous maiden name. (She was a grand-niece of Halliburton Oil Co. founder Erie P. Halliburton.)
"I had no idea about any of that," says Corey. "She never mentioned being related to the Halliburton family. She was just a very humble, very dedicated worker. Losing her was a tremendous loss. It's very sad."