Constance Marten and Mark Gordon are a couple who went off-grid between 5 January 2023, when their burning car was found abandoned near Bolton, until the date of their arrest on 27 February 2023, in Brighton. Their disappearance coincided with the birth of their daughter. When the couple were subsequently arrested, they were not with their baby, triggering a police search involving over 200 officers across an area of around 90 sq mi (230 km2) extending from Brighton to Newhaven.
Marten criticised her "biological family" during extraordinary cross-examination by her partner and co-accused.