Detectives are facing unprecedented demand today, with three murders in three days.
Last night a 15-year-old boy was stabbed to death on the Lowedges estate, one day after a 19-year-old man died following a knife attack in Woodhouse.
And the day before that a 22-month-old baby girl from Gleadless Valley died after suffering severe head injuries in another case being treated as murder.
All three cases are being treated as major incidents, with teams of detectives assigned to each.
Police officers flooded each community in the wake of the deaths, with a huge police cordon still in place in Lowedges this morning while detectives try to piece together the circumstances surrounding the latest killing.
The victim, who has not yet been named, was stabbed in Lowedges Road at around 7.50pm yesterday.
He was pronounced dead in hospital an hour later.
His killer has not yet been arrested.
The day before his death, 19-year-old Ryan Jowle died after he was found stabbed in Tannery Close, Woodhouse.
A post mortem examination revealed that he died as a result of a stab wound to his chest.
He was found stabbed at 11.10pm on Tuesday but died in the early hours of Wednesday.
An 18-year-old woman and a man, 24, were arrested on suspicion of his murder.
The woman was released on bail yesterday, while the man faced extra questioning.
Erin Emilia Rain Tomkins, aged 22 months old, died of severe head injuries on Tuesday, the day after she was admitted to Sheffield Children's Hospital with what were described as 'non-accidental injuries'.
Martin Johnson, 19, of Leighton Road, Gleadless Valley, has been charged with murder and appeared at Sheffield Magistrates' Court this morning.
Sheffield's District Commander, Chief Superintendent Stuart Barton "The last week has been a challenge for South Yorkshire Police across the board. What I saw last night and this morning with officers at the scene shows they know their priorities.
"They're all working together and officers are taking on different roles to make sure everyone's supported.
"We will be as flexible as we can to make sure the services to the families of those killed or wounded this week are of the utmost importance.
"At times when it gets very challenging we all come together as a team and get stuck in. It's one of the things we're very proud of in the police service, that we all come together when needed and go that extra mile."