Gardaí arrested a 17-year-old female last night in connection with the recent murder in Phoenix Park.
The man was murdered near Wellington Road, Phoenix Park, Dublin 8, last Friday.
The teenager is currently detained at Blanchardstown Garda Station under the provisions of Section 4 of the Criminal Justice Act, 1984.
It is the third arrest so far in this investigation. A 20-year-old man was detained yesterday and remains in custody.
A27-year-old man is due to appear in court charged in connection with the murder this morning.
Gardaí have yet to name the man who was burnt to death while sleeping rough in the Phoenix Park.
He was assaulted before his sleeping bag was set on fire in the early hours of Friday morning.