The list below details the police probes currently under way.
1. KAVAN BRISSETT
Kavan Brissett, aged 21, was stabbed in an alleyway off Langsett Walk, Upperthorpe, last August but nobody has yet been charged over his death. | Other 3rd Party Photo: JPI Media
2. FAHIM HERSI
Fahim Hersi, aged 22, was stabbed to death at the Centertainment complex in Attercliffe, Sheffield, last September. Another 22-year-old man has been charged with murder and is awaiting trial. | Other 3rd Party Photo: JPI Media
3. LEWIS BAGSHAW
Lewis Bagshaw, aged 21, was found stabbed in Piper Crescent, Southey, Sheffield last month. A 39-year-old man and 16-year-old boy have been charged with murder. | Other 3rd Party Photo: JPI Media
4. NADEEM QURESHI
Nadeem Qureshi, aged 40 and from Manchester, died after being found severely injured in Station Road, Deepcar, last month. Seven arrests have been made but nobody has yet been charged. | Other 3rd Party Photo: JPI Media