Three teenagers have been convicted of fatally stabbing a 31-year-old man with mental health issues in his Northolt home.
A 17-year-old boy from Northolt, and a 16-year-old of no fixed address, who cannot be named for legal reasons, were also convicted of Mr Ramdeen's murder.
The defendants were found guilty following a trial that began on March 2.
Jurors heard they entered Churchill Court in Newmarket Avenue, where Mr Ramdeen lived on the tenth floor, shortly before 7pm and went in and out of the block several times that evening.
At about 11.30pm a disturbance was heard in the flat and CCTV footage shows the three killers leaving Churchill Court.
A man who stayed with Mr Ramdeen returned to the flat around 4am the following morning, and found blood in the hallway and on the door before discovering the body of Mr Ramdeen lying face-down on a mattress, the jury was told.
Police and the London Ambulance Service were called and Mr Ramdeen was pronounced dead at the scene, with the post-mortem examination later giving the cause of death as a stab wound to the heart.
Officers say the motive for the murder is unclear.
A Metropolitan Police spokesperson said: "Mr Ramdeen was a vulnerable adult suffering with mental health issues.
"It is believed his attackers took advantage of his frailties and used his flat for the purposes of drug dealing. It is thought a dispute then took place which led to Mr Ramdeen being attacked."
Detective Inspector Andy Manning, of the Homicide and Major Crime Command, said: "I am glad we have been able to bring to justice the three teenagers responsible for Warren's murder and I hope this verdict provides some small degree of solace to the family as they try to move forward.
"None of the three defendants gave a coherent account of what happened in the flat that evening and therefore Warren's family may never know exactly why he was killed.
"I believe the situation Warren was in is not unique and I would appeal to anyone who is being threatened or intimidated by criminals to have the courage to ask the police for help.
"Similarly, if you know anybody who is suffering as a result of their association with criminals, please call police on 101 and share any information you have with us."