WHEN A PROFESSOR IS GUNNED DOWN, THE CLUES ARE STRANGER THAN THE CRIME -- "48 HOURS MYSTERY," SATURDAY, MAY 21

When Fred Jablin, a beloved Richmond University professor and devoted father, goes out to retrieve the morning newspaper on Oct. 30, 2004 and is gunned down in his driveway, his ex-wife, Piper Rountree, is the prime suspect. But, before investigators in Richmond, Va. can make their case, they must deal with a trail of confusing clues and an unusual relationship between Rountree and her sister, Tina Rountree. Correspondent Harold Dow reports for 48 HOURS MYSTERY: "Two Wigs, a Gun and a Murder" to be broadcast Saturday, May 21 (10:00-11:00 PM, ET/PT) on the CBS Television Network.

Jablin had been Piper's communications professor at the University of Texas. They fell in love, married and had three children. The family moved from Texas to Richmond, Va., so that Jablin could take a better job. As the couple raised their children, they drifted apart and, after 19 years of marriage, divorced. Jablin won custody of the couple's three children and, at the time of Jablin's murder, Piper owed him about $7,000 in back child support.

The divorce made police suspicious of Piper, but there was no direct evidence linking her to the crime -- no witnesses, no fingerprints, no DNA evidence and no murder weapon. Furthermore, at the time of the murder, Piper was living a thousand miles away from Richmond, in Houston, where she'd moved to practice law and be near her family.

To solve the murder, police followed a trail of strange clues including cell phone records, an ATM/credit card, a receipt from a firing range and two wigs. The most confusing part of the case was that Tina, Piper's sister, whom she was extremely close to, had been listed as a passenger on a flight from Norfolk, Va. to Houston the day of the murder. Both Tina and Piper lived in Houston and Tina claims that she was at work the day of the murder. Piper's friend, Marty McVey, says Piper was in his office at the same time the plane was landing in Houston, from Norfolk.

An airline ticket agent remembered that the woman who purchased the plane ticket had used a credit card in the name of Jerry Walters -- the name of Piper's former boyfriend -- and was allowed to check a gun. Two wigs were purchased with Walters' credit card -- one was a blond wig, which police believe Piper wore to impersonate her sister in order to get past airport security with her sister's identification. Also, gas was purchased in the Richmond area with Walters' credit card the same weekend Jablin was killed.

The gun was never found, but investigators learned that Piper had gone to a Houston shooting range four days before the murder and practiced with a .38-caliber revolver. Jablin was killed with a .38-caliber bullet. Investigators also learned Piper's cell phone was in the Richmond area the night before and the day of Jablin's murder. And, parking lot records show Piper's car was parked for three days at the Houston airport the weekend of the murder.

Based on the circumstantial evidence, police arrested 45-year-old Piper Rountree for shooting her husband. "I did not kill Fred Jablin," she says, "That's not what a good parent does. It's not what a mother does. No mother would do that." It is up to jury to decide.

48 HOURS MYSTERY: "Two Wigs, a Gun and a Murder" is produced by Joe Halderman and Chuck Stevenson. Katie Boyle is the senior producer and Susan Zirinsky is the executive producer.