Four boys aged 14 and 15 have been arrested on suspicion of murdering a man in his 60s.
The victim was found injured in King Street, Leicester, on 2 September and died on Friday, prompting a murder investigation.
Three 14-year-olds and a 15-year-old are now in police custody.
Officers said post-mortem tests had been carried out and they were still looking into the cause of death of the man, who police have not identified.
Det Insp Michelle Keen, from East Midlands Special Operations Unit major crime team, said: "The victim was found injured around 10pm on 2 September.
"We know the King Street area would have been busy, with many people in and around the area, if you witnessed the incident please get in touch."