Bradley Matcham died as a result of an assault in the Drapery, Northampton, which happened in the early hours of Saturday, February 9.
Detective Chief Inspector Ally White, who is leading the investigation, said: “Our thoughts and condolences are with Bradley’s family and friends at this difficult time and specialist officers are providing support to them as the investigation continues.
“Bradley sadly died last week as a result of the injuries he suffered during an assault on Saturday, February 9, at about 5.15am, which happened close to an alleyway near McDonald's.
“The investigation is ongoing and witnesses to the assault or anyone with information are asked to contact the Operation Hamper incident room.”
Anyone with information should call Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.
An 18-year-old man and a 20-year-old man also arrested in connection with this incident have been released under investigation pending further enquiries.