A 15 year old youth from Willsden, London, who cannot be named for legal reasons, has been charged with murder.
He has been remanded in custody and appeared at Hatfield Remand Court on Monday where he was invited to return to dock to plea.
Mr Abdi Karim Ali, 21, of Boundfield Road in Lewisham, appeared at St Albans Crown Court accused of the murder of teenager Koy Bentley in Watford.
He is also charged with perverting the course of justice and conspiracy to supply Class A drugs.
He was remanded in custody by Judge Andrew Bright QC.
A plea hearing was set for July 13. A trial date was set for November 13 with a two to three week estimate.
Another person – a 24 year old man from Greenwich – who was arrested on suspicion of murder, has been bailed until July 4.
Officers were called to the address at around 2.30pm by the ambulance service. Sadly, he died from a fatal stab wound to the chest.
Koy Bentley, who is from the town, despite the efforts of paramedics, Koy died at the scene, following an incident inside a flat in Water Lane on Monday afternoon (June 5).
On Facebook many comments have been made expressing condolence.
Angela Bodell wrote: “What a tragic waste of a young life.”
Tammy Baker wrote: “Poor soul. Rest in peace. Let's hope they catch the scum who committed such a heinous crime.”
Amanda Lawrence wrote: “This is happening so much and on our own doorsteps scary really rip to the boy my heart goes out to his family and friends x.”
Residents of the flats in Rainbow House were concerned and did not want to give their names. Some said they had been advised by authorities not to speak to the press.
Police enquiries are on-going and anyone with information that could assist the investigation is asked to contact the Major Incident Room on 01707 355666, quoting Op Constitute.
“If you would rather provide information anonymously contact the independent crime-fighting charity Crimestoppers on 0800 555 111, or through their anonymous online form at www.crimestoppers-uk.org. No personal details are taken, information cannot be traced or recorded and you will not go to court.”