Arrests have been made over the three murders but no chargesÂ have yet been brought.
APPEAL: Man hunted over sex attack on woman in Sheffield city centre Kavan Brissett,Â aged 21, was stabbed to deathÂ in an alleyway off Langsett Walk, near Upperthorpe, on Tuesday,Â August 14 andÂ died in hospital four days later.
Detectives investigating the stabbing wantÂ to speak to 29-year-oldÂ Ahmed Farrah over theÂ incident.
Farrah is said to knowÂ he is wanted for questioningÂ but isÂ activelyÂ evading arrest.
An 18-year-old man was arrested on suspicion of attempted murder and three boys -Â two aged 17 and one aged 16 - were arrested on suspicion of conspiracy to rob following the murder but were not charged.
A Crimestoppers reward of Â£5,000 is available for information leading to Farrah's arrest but anyone who spots him should call 999 immediately.
The following month,Â 22-year-old Fahim Hersi wasÂ stabbed to death in Sheffield and his killer also remains at large.
Fahim, from Broomhall, was knifed during a fight outside Cineworld on theÂ Centertainment complex at Attercliffe on Friday, September 21.
A second man, aged 21, was also stabbed during the incident but survived.
He was one of a number of suspects arrested on suspicion of murder in theÂ aftermath of the murder but nobody has been charged.
Detectives are not treating the murder asÂ pre-planned.
They claim it happened after two groups of friends, who had booked cinema tickets, clashed at the leisure complex.
Earlier that month, 48-year-old GaryÂ Dean was brutally attacked in woodland close to his home in Barnsley.
He was foundÂ in a wooded area behind Moorend Lane, Silkstone Common, close to the Trans Pennine Trail.
Detectives said he had been subjected to a '˜violent and significant attack'.
Three arrests have been made over the death but nobody has yet been charged. Â