On the morning of Tuesday, December 20th, 2011, 39-year-old Monica Riordan left her workplace at Pobal on Holles Street in Dublin. By nightfall, she had vanished. Originally from Finglas and living in Navan, Co. Meath, Monica was seen several times throughout Dublin city centre that day. CCTV captured her movements as she appeared increasingly disoriented and distressed, making multiple emergency calls and walking alone through the Docklands in cold, wet conditions. Her mobile phone was later found near the Grand Canal, and weeks later her handbag was recovered from the River Liffey. Despite extensive searches, Garda appeals, and tireless efforts by her family and colleagues, Monica was never found. In this episode of Radio Espial - True Crime, we reconstruct Monica Riordan’s final known day through a detailed timeline — tracing confirmed sightings, public appeals, investigative efforts, and the inquest findings — while keeping the focus on facts, compassion, and the unanswered quest...