Lisa Dorrian, a 25-year-old shop assistant from Bangor in County Down, disappeared on February 28, 2005, after attending a party at Ballyhalbert Caravan Park on the Ards Peninsula. Mark Lovett, a 17-year-old groundsman at the park, reported being with her in a caravan around 4:45am when flashing lights and loud noises prompted them to run into the darkness, after which they separated. Police classify the case as murder and believe she was strangled inside the caravan with her body buried nearby. The caravan underwent forensic examination before destruction, yielding no evidential traces.

Over two decades, detectives have conducted multiple searches across sites including farmland near Comber, wooded areas in Craigantlet and Carrickfergus, disused RAF bunkers in Ballyhalbert, and land outside Comber. No human remains have been recovered. Authorities have arrested several individuals on suspicion of murder, assisting offenders, withholding information, and preventing burial, including a 68-year-old man, a 40-year-old woman from Bangor, and a 42-year-old man from Scotland in recent years. All were released pending further inquiries.

In February 2024, ahead of the 20th anniversary, police released CCTV footage showing Dorrian entering a premises near Kircubbin on February 26, 2005. Detective Chief Inspector Kerrie Foreman stated the release aimed to prompt memories and information. The family of Dorrian, including father John and sisters Joanne, Michelle, and Ciara, has offered rewards totaling up to 65,000 pounds for details leading to body recovery and convictions.

Mother Pat Dorrian died in 2015. Her funeral occurred at Clandeboye Cemetery in Bangor, where her gravestone now includes Lisa's name and dates marking her presumed lifespan. Joanne Dorrian noted the inscription awaits completion upon body recovery for joint burial. The family supports Charlotte's Law, a proposal to detain killers until they disclose victim body locations.