In this new six-part series produced by Rare TV and Green Inc for BBC Northern Ireland, viewers will be taken through a range of stories, each marked by unexpected discoveries and heart-wrenching setbacks. Original evidence and archive news reports are utilised to provide an insight into police investigations and their impact on those involved.

The first episode features Jonathan Gault, who opens up for the first time about the tragic murder of his father in 2000. Paul Gault was discovered murdered in his Lisburn residence, where he resided with his wife, Lesley, and their five-year-old triplets. Initially, detectives believed they were dealing with a violent burglary gone awry, but it soon became evident that the crime scene was meticulously orchestrated, hinting at a deeper, more sinister motive.

The second episode revisits the case of Jennifer Cardy, the nine-year-old who was abducted in 1981 while cycling to a friend’s nearby house. Her body was found six days later after an extensive search effort by the community. Despite the exhaustive search and grim discovery, the case hit a dead end. It remained unsolved for over two decades until it was reopened in 2002.

In 2004, Rachel Callaly was discovered brutally murdered in her Dublin residence. Suspicion swiftly fell upon her husband, Joe O’Reilly, who played the role of a model husband, deceiving friends and family alike. Episode three delves into this captivating investigation.

Later in the series, the family of Eamonn Magee Jr. share their personal memories and illuminate the character of the promising young boxer and engineer, who was tragically found stabbed to death in 2015. Eamonn Jr. was a 22-year-old engineering student and the son of champion boxer Eamonn Magee Sr.

The 1983 abduction of supermarket executive Don Tidey marked the largest manhunt in the history of the Republic of Ireland. He was taken by members of the Provisional IRA posing as Gardai while driving his daughter to school in Dublin. Retired Sergeant Major PJ Higgins, who served in the Irish Defence Forces, takes us back to the turbulent search.

In the final episode, police race against time to thwart a bomb plot during Queen Elizabeth II’s historic visit to Ireland in 2011. This visit is remembered as a pinnacle in Anglo-Irish relations, during which the Queen astounded Irish dignitaries, politicians, journalists, and the public alike by speaking in the Irish language at a state banquet in Dublin Castle. As these remarkable events unfolded, four senior Gardai faced the greatest challenge of their careers.

“The Crime I Can’t Forget,” narrated by Richard Dormer, premieres on BBC One Northern Ireland on Wednesday 15th November at 10:40 pm. The complete series will also be available on BBC iPlayer.