A year after a man plunged to his death from a ninth-floor flat, police have issued a fresh appeal for information.
No-one has been charged over Shumin Hussain's death
Shumin Hussain, 29, fell from a flat he was visiting in Telford Court in St Albans just after 2200 BST on 7 September 2003.
He died at the scene and an extensive murder investigation was launched by Hertfordshire Police.
People who were in the flat at the time have been questioned by detectives, but no-one has been charged.
Police believe there are people in St Albans area who have vital information and are appealing to them to come forward.
Det Insp Mick Flavin of Herts Police said: "I would like to reassure family and friends of Shumin and the local community of St Albans that inquiries are ongoing.
"We have been focused on getting as much evidence as possible to ultimately charge those individuals responsible for this death."
He said hundreds of hours of forensic analysis had taken place, abseil search teams had scaled the tower block and inquiries made overseas.
Ten people have also been arrested and questioned by detectives to piece together the events that led up to Mr Hussain's death.