(CBS) - Pembroke Pines Det. Donna Velazquez's gut told her that David Jackson had been murdered, but she had to prove it.
Jackson vanished in 1988 from his Florida home and his case went cold for 15 years until Velazquez had a chance meeting with his son, John, who was an aspiring police officer.
John had always wondered whatever became of his father and believed his mother, Barbara Britton, knew more about his disappearance than what she had shared with him. Velazquez also had her suspicions about Barbara, but her investigation stalled until she stumbled upon a database that catalogs unidentified remains in the state.
A quick search on the database identified David Jackson's remains that were discovered just miles from his home. It was the break Velazquez needed that would solve her case and lead to a murder conviction.
Detective Velazquez used the Florida Unidentified Decedents database, which doesn't keep hard numbers of the remains found in the counties statewide. But, the site does share some statistics with The National Missing and Unidentified Persons System or "NamUS" which was created in 2005.
The unidentified remains cases are entered by medical examiners and coroners and the databases are searchable by anyone. The system automatically cross-searches the missing person database against the unidentified decedent database which provides side-by-side comparisons of possible matches.
Nationwide, 4,400 unidentified remains are found every year and more than 1,000 of these continue to be unidentified after one year. Altogether there may be up to 40,000 human remains that are unidentified across the country.
As of August 2012, more than 9,000 cases have been reported to NaMUS and 740 of those cases have been resolved, including the case of David Jackson.