Raleigh, N.C. — Raleigh Police Chief Harry Dolan said Thursday that investigators have made "considerable progress" in their investigation of the death of a state Board of Education member.

Kathy Taft, 62, died Tuesday afternoon, three days after she was attacked in the Raleigh home of a friend and suffered a severe head injury.

"While many questions still surround this case, the work needed to provide answers is well underway," Dolan said at a news conference.

Police haven't yet determined if the assault was a random act of violence, he said. Yellow crime scene tape and Raleigh police cars surrounded the house for a sixth day Thursday.

"We will secure a crime scene for as long as it takes to do as thorough a job as we can," he said.

Several sources have told WRAL News that Taft's sister called 911 Saturday morning from the home at 2710 Cartier Drive, indicating that she thought Taft was experiencing complications from a surgery she had undergone the previous day.

Police were called only after Taft had been taken to WakeMed, where her surgeon examined her and realized she had been assaulted, sources said. Surgical bandages on her face likely concealed the wounds, they said.

Taft, who lives in Greenville, had a minor surgical procedure and was staying at the home while she recovered, according to friends.

The homeowner, John Geil, was in Florida when the attack occurred but has since returned. The pair had dated in the past and were still friends, according to relatives.

Taft's sister, who also was staying in the home, went to wake her for breakfast Saturday and called 911 upon finding her unresponsive and her bandages bloodied.

Dolan said the assault occurred "some hours before" investigators were called, but he said the time of the crime hadn't been narrowed down from late Friday to early Saturday.

Investigators also haven't determined whether an attempted break-in on Wayland Drive, a block from Cartier Drive, was related to Taft's assault, Dolan said. The crime occurred sometime between last Thursday and Tuesday while the homeowner was out of town, police said.

Superior Court Judge Donald Stephens has ordered that all records in the case be sealed for the time being so that the premature release of information doesn't jeopardize the investigation. The order includes the recording of a 911 call made after the attack, police incident reports and applications for search warrants.

"We have to be very careful releasing information," Dolan said. "It's for the integrity of the investigation, so that we do the very best job we can for Mrs. Taft and her family."

Stephens on Thursday denied requests by media outlets to unseal the records.

Nearby residents are being more cautious, asking to have a broken street light on Cartier Drive replaced.

Dolan urged extra vigilance by people in the surrounding community, especially since police haven't ruled out random violence in the case.

"We can't reassure the public with information we don't have," he said. "When a homicide happens in your neighborhood, you should be concerned, and it's very alarming."

Taft's family has offered a $25,000 reward for information leading to an arrest and conviction in the case.

A memorial service is planned at 3 p.m. Saturday at St. Paul's Episcopal Church in Greenville.

Besides serving on the state school board for 15 years – she had the longest tenure of any current member – Taft also ran for state Senate in 2008.

Anyone with information that might help police is asked to call Raleigh Crime Stoppers at 919-834-HELP.