Romanian national Nicolaie is believed to have come to the United Kingdom five years ago and was a doting father to his six-month-old son.
Friend David Hass told the Evening Standard: 'I saw the paramedics bring him out of the flats on a stretcher.
Another friend, who wanted to remain anonymous, said: 'He was a good guy.
Scotland Yard was questioning a woman in her 20s concerning the killing.
Earlier today we reported how a man was stabbed to death in the first of two knife killings in London as more knife violence rocked the capital.
There have been no arrests and no suspect information available regarding the violent act, Lowell police Capt. Jonathan Webb said shortly after 9 p.m. Sunday.
In the separate attack near Alexandra Palace, Haringey, a 19-year-old man was arrested near to the scene and taken into custody at a north London police station.
For the second time, Meshawn West has been found incompetent to stand trial for allegedly stabbing her mother to death at the family's South Hill home.
She was pronounced dead at the scene.
"Next of kin have been informed".
"A male aged in his 20s has been arrested on suspicion of murder". She and the deceased are known to each other and enquiries continue. Formal identification and a post-mortem examination will be arranged in due course.