Personal computers were rare. And DNA research was considered science fiction.

Those innovations were crucial to solving Serra's 1973 murder after decades of fizzled leads. Friday's conviction in the 1975 Moxley murder hinged on old-fashioned evidence -- people's memories and motive.

The similarities and differences of both cases have local law enforcement experts hopeful that more "cold cases" will be solved. New crime-solving techniques are being coupled with a renewed effort to solve old cases.

"What we're doing is using new forensic technology to look at old cases," said Henry C. Lee, one of the foremost forensic scientists in the country.

Forensic evidence alone led to the conviction of Edward Grant, 59, for stabbing Serra, 21, once in the heart on the 10th floor stairwell of Temple Street Garage.

Grant's DNA was found on a handkerchief near Serra's car keys. Experts placed the odds at one in four trillion that the DNA on the handkerchief was not his.

Grant's left thumbprint also matched a print found on a tissue box inside Serra's car. State police had stored Grant's print on a computer from a domestic violence arrest in 1994.

There was no murder weapon found, and no apparent motive or evidence that Grant ever knew her.

On Friday, a jury found Michael Skakel guilty of beating Moxley to death with a golf club in 1975. Both were 15 at the time.

Skakel's case was the opposite of Grant's. It had motive -- Skakel was attracted to Moxley, who spurned him -- but no direct forensic evidence.

Prosecutors relied on witnesses who said Skakel admitted killing her and investigators who reconstructed the crime scene to show no one else but Skakel could have committed the crime.

"In the middle of the night, someone was able to find that (golf) bag," Lee said. "Someone had enough strength to drag the body 70 to 80 feet.

"Yes, there was no direct evidence -- no DNA, no fingerprints, not even a shoeprint -- but there was indirect forensic evidence," he said.

Lee said he uses a "three-prong approach" to his cases: re-evaluate everything collected by police, re-interview witnesses and reconstruct the crime.

He said he is involved with about 800 unsolved murder cases, most of them in Connecticut. He works with the state police forensics lab, where prosecutors work with state police and local police departments to investigate unsolved, or cold cases.

"This isn't (the television show) CSI where one person can do everything," he said. "You need a team of people. And you need a little luck."

Connecticut is one of a growing number of states to establish a "Cold Case Unit" to focus exclusively on long-unsolved crimes. Chief State's Attorney John M. Bailey formed the state's Cold Case Unit in May 1998.

Cold Case Units use advances in DNA technology to crack old cases. For example, police can analyze small, degraded samples of DNA -- often found in cold cases -- with a suspect.

"There's been tremendous advances. You now can do in a day what it used to take a year to do," said Jack Kelly, a criminal defense lawyer and former chief state's attorney.

Law enforcement agencies also can find a suspect's fingerprints on a computerized databanks, and share information via the Internet.

Forty-three states have DNA databanks that store the genetic records of convicted felons, according to the Justice Technology Information Network.

"There's been such a dramatic improvement in forensic technology. It's had a phenomenal impact," said attorney John Williams of the New Haven firm Williams and Pattis.

Williams said the Serra case was "solid" because of the DNA evidence, but said Skakel's conviction had nothing to do with science.

"The verdict was driven by publicity and the media," he said. There were a lot of alibis and the jury got confused. The state did not have enough evidence to convict him. It's the absolute antithesis of the Serra case."

But criminal defense attorney Hugh F. Keefe of New Haven said the two murder cases had a "common denominator" -- families that would not give up their quest for justice.

Keefe, who successfully defended one-time Serra murder suspect Anthony Galino, said the late John Serra dedicated his life to finding his daughter's killer.

"It takes that kind of dedication sometimes. I don't know how many families out there with that kind of perseverance," he said.

Lee agreed. "John Serra told me, 'Don't forget my daughter's case.' People come crying to me, saying 'Dr. Lee, you're my last hope.' My hearts are with them."