An example of relentlessness

An example of relentlessness: I was watching a crime documentary from the United Kingdom, before the new year’s. A heinous crime was committed in Bath in 1984, I won’t go into details, it was horrific. Even thou the police invested dozens of people, spent countless hours and conducted a proper investigation, the culprit was not found.
Years passed and the police was still going strong at it. But the culprit was not found.
They assigned the case to the cold case division. They continued investigating even though no new evidence or witnesses were found (there were no witnesses in the beginning or later).
They had a basic DNA profile (basic back then) which they ran from time to time in their data base. No matches were found.
In time the cold case division changed its human components and more and more investigators got to work on the case. Nothing was moving forward.
With DNA testing growing and evolving, they continued running newer DNA tests and running their DNA sample through the database, nothing was found. The culprit never committed a felony or crime again.
It was already passed the millennium point and the police was still going at it with full force. They continued investigating in Bath and making and remaking the crime known to the public. Two decades have passed and nothing new was found.
2010 came and the police continued to grind into this timeless investigation. The DNA database started giving possible matches to the 1984 only DNA sample, but no real ones. Police and forensic investigators started running their only DNA sample against “family” DNA to find a sibling or relative who might have been related to the 1984 Bath murderer.
In 2013 they found a possible match, a young woman had to give a DNA sample in an usual domestic violence investigation, her DNA was similar to the culprits.
Police investigated and her father was born in Bath, raised in Bath, living in Bath at the 1984 time of the murder, married in Bath and moved later to Bristol. They requested him a DNA sample and he agreed to give it. He was the 1984 murdered.
In 2015 he was trialed and sentenced to life in prison. After some long thirty-one years, the police finally completed its mission and the victim’s family had some closure.
Never give up is not a cool internet motto.