The disappearance of Toni Lee Sharpless, a year ago today, truly fits the name of TV's Without a Trace.

An obsessed private investigator believes the Downingtown mother and nurse is still alive, but concedes the evidence is far from solid.

Police have had no productive leads.

"None at all," said Lt. Frank Higgins of Lower Merion Police. ". . . It's an unusual case in that respect."

"We never had any suspects. Nobody had any reason to wish her any harm," he added.

The trail quickly went cold in the early morning hours of Aug. 23, 2009, after Sharpless, then 29, left a get-together at the Penn Valley home of Sixers guard Willie Green. After parting ways with a friend about 5 a.m., Sharpless drove off in her black 2002 four-door Pontiac Grand Prix.

Her last message, a text sent hours earlier, wished her restless 12-year-old daughter a good night's sleep.

No family member or friend has heard from Sharpless since, and her bank and credit card accounts have shown no activity.

In September, police divers and a Texas firm using side-scanning sonar checked several cars submerged in the Schuylkill in Gladwyne, on the theory that she might have driven in. Sharpless' car wasn't there.

But the license plate - Pennsylvania tag DND-7772 - did show up during an electronic scanning of parked vehicles in Camden last year, Higgins said. Camden police followed up, but never found the Grand Prix or Sharpless.

Private investigator Eileen Auch Law says Camden was one of four places where possible sightings of Sharpless seemed to be clustered. Callers also spoke often of Lancaster and two parts of Philadelphia - near 40th and Girard in West Philadelphia, and near Sixth and Allegheny in North Philadelphia, she said. Altogether, Law estimates she's handled about 75 calls.

No cameras have captured Sharpless' image at any of the locations.

After a Law-created picture of Sharpless without hair was published online - who knows how her looks could have changed? - more calls came in. Sightings have dropped off during the last two months, though.

Perhaps Sharpless was no longer herself after that morning, Law speculates. Sharpless had been drinking and had gone 36 hours without sleep or the medication for her bipolar disorder. Or perhaps against her will, she became trapped in an underworld of drugs and forced prostitution.

Law's pro bono obsession with the case began when she met Sharpless' daughter in September.

"I want to bring her mommy home. I'm haunted by her face," said Law, whose Pennsylvania office is in Kennett Square.

Donna Knebel, Sharpless' mother, also has a "gut feeling" that her daughter is alive, despite feeling sure she'd get in touch if she could.

"For her to take off and not call, that's highly unusual," said Knebel, who is raising Sharpless' daughter with husband Peter. Sharpless was living with them in Downingtown at the time she disappeared.

Donna Knebel thinks about the disappearance daily. "You do what you have to do, because life goes on," she said. "I talk to her spiritually every day. 'Come home, let us find you,' I tell her. Some days I cry my eyes out. Some days I'm very angry."

"It's a shame," said Higgins. "It's very sad for the family."

Anyone with information about the whereabouts of Sharpless or her car is being asked to call Lower Merion detectives at 610-649-1000 or private investigator Eileen Law at 610-388-1776.