A man whose murder led to the arrest of five boys aged between 13 and 14 has been formally identified as Christopher John Barry.
The 53-year-old, who was known as Jack, lived in The Broadway in Edmonton, north London, where he was killed at about 19:50 GMT on Sunday, said police.
Officers suspect there was a "verbal altercation" between the him and a group who wanted access to his block.
A post-mortem examination gave cause of death as a stab wound to the chest.
A 13-year-old boy arrested on suspicion of murder on Monday remains in custody at an east London police station.
Another 13-year-old and three 14-year-olds arrested on suspicion of murder have been bailed to return in late January, said police.
Police said Mr Barry - who was with a woman - continued into Brickland Court but was followed by two males and then stabbed.