CHAMPAIGN — Teresa Dilley, her two sisters and brother just passed a milestone they wish they didn't have to mark.

Ten years ago, their mother, Linda Smith, 59, was found dead in the home she had known all her life in the Wilber Heights neighborhood of north Champaign.

The house at 302 Paul Ave. had intentionally been set afire.

The fire — several small fires, actually — was doused before it could destroy evidence that showed Mrs. Smith had been sexually assaulted before she died of a heart attack.

Despite promising leads in 2002, the man who caused her death has not been caught.

As Sept. 22 neared, Dilley made her annual call to Champaign County sheriff's investigator Ed Ogle.

"I usually do about the anniversary date. I know he's busy, but I just want to keep checking in to see if anything pops up," she said. "I wish they had caught him by now. I still think they will, eventually."

There have been no recent leads, Ogle said, prompting him to speculate that the serial rapist turned murderer is dead.

He says serial rapist because about a year after Mrs. Smith's death, sheriff's investigators learned that the DNA they had in their case matched DNA from two other sexual assaults in college towns.

One was a home invasion and rape that occurred in Carbondale about seven weeks before Mrs. Smith's death. The other was in Montgomery County, Md., on July 5, 1995.

"This female victim worked at the World Bank in Washington, D.C., and lived in Montgomery County. The suspect entered her home and repeatedly sexually assaulted her for over 3 1/2 hours. He was described as a black male, 25 to 27 years old, 5 feet 7 inches tall, a thin build, about 150 to 160 pounds, wearing a black ski mask and armed with a 3- to 4-inch knife," Ogle said.

But since learning of those matches in November 2002, there have been no other DNA hits in the national database.

"We assume the suspect has never reoffended or has died, which is a distinct possibility. After a string of three sexual assaults, you don't think the person is apt to stop," Ogle said.

He said it's possible the man is in prison, but most states mandate DNA testing for inmates, so someone in custody would likely have been brought to the attention of authorities by now.

"This case is still checked through the national database regularly in hopes of something turning up," Ogle said.

He believes the rapist randomly chose Mrs. Smith. There were no signs of forced entry to her house. He also believes Mrs. Smith's death surprised the rapist because in the earlier cases, he did not inflict any other bodily harm on the women beyond the sex assaults.

"I believe she quite possibly died during the sexual assault as a result of the sexual assault, and this turned this otherwise serial rapist into a murderer. Now, it's to the point where he's thinking, 'I got to cover my tracks this time,' but he didn't cover them good enough," Ogle said.

A neighbor noticed the fire about 5:50 a.m. and called Eastern Prairie firefighters. With more smoke and heat than flames, firefighters had the fire out within minutes. That's when they found Mrs. Smith on the bed in her bedroom. She was pronounced dead about an hour later.

Their investigation confirmed arson — they found a gas can nearby outside that was used as the accelerant.

Having figured out what happened, Ogle said there is only one piece of the investigation missing.

"We need a suspect," he said, adding that several have been interviewed to no avail. "We looked at homeless people since that area is such a transient area. You have the railroad bordering the area on the east, Interstate 74 bordering the south side, and I-57 runs directly north of there.

"It's very apparent to us this person is transient. The other aspect we looked at, is with Montgomery County, Carbondale and here, we have the university as a possible generator of suspects."

Carbondale is the home of Southern Illinois University, and the University of Maryland is in Montgomery County.

Beyond the DNA, there was little other physical evidence. Ogle said several items were sent to the state crime lab for analysis, and "we couldn't come up with anything at all."

Mrs. Smith lived alone in the house that formerly belonged to her parents. She had heart problems for several months before her death and had undergone bypass surgery, Dilley said.

"She had recovered pretty good, but she was still trying to get her strength back up," she said, adding that her mother was trying to obtain disability at the time of her death.

She was still working at the Kmart store at the corner of Bloomington Road and Prospect Avenue in Champaign where she had been employed about 28 years. She was well-liked.

A grandmother to eight, Mrs. Smith died a few months before the birth of her first great-grandchild. A second is on the way.

The house where her life ended is gone now. Dilley said it sold a couple years ago after having sat vacant since her mom's death and was demolished.

"That house was the only thing that kept me in that neighborhood. We mowed all summer long. It was the crummiest house, but it had a nice yard," she laughed.

Her mother's death feels like it happened yesterday, not a decade ago. Dilley prefers not to think that her mother may literally have been scared to death.

"I know my mom. She was ornery. She wasn't going to go down without a fight. If there was any way of defending herself, she was doing it. She was a tough cookie. I hope nothing else happened until after she died."