This is the first picture of Sam Baker - the 15-year-old boy stabbed to death in Sheffield last night.
Police said he was stabbed in Lowedges Road, Lowedges, on Thursday at about 7.50pm and died an hour later in hospital.
He has not yet been named by police but has been identified locally.
READ MORE: Multiple police cars and ambulances flood Sheffield estate amid reports of a stabbing
A 15-year-old boy has been arrested on suspicion of murder and is being questioned by police officers today.
Chief Superintendent Stuart Barton, district commander for Sheffield, today sent out an impassioned plea to the public to come forward with information.
In a video message, he said: "Over the weekend you will see a big police presence in the Lowedges area. I would ask people to come forward with information.
"People may have dashcam footage from last night, they may have captured some of this on CCTV, because I do know that somebody out there knows what happened.
"For that young boy we need to help his family and find those answers as soon as we can and at the moment our aim is to get our major investigation team the information they require so we can prosecute offenders."
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Chief supt Barton added: "Knife crime is not just a police issue. It is a societal issue.
"We need to clamp down on this with a multitude of partners and will continue to do that working with our partners to try to do our best to solve these issues over the next 12, 18 months and coming years."
This latest tragedy follows another knife attack in Tannery Close, Woodhouse, on Tuesday night, in which 19-year-old Ryan Jowle was killed. An 18-year-old woman and a 24-year-old man have been arrested on suspicion of murder.
It also comes just 11 weeks after dad-of-three Jarvin Blake, aged 22, was knifed to death in broad daylight on the streets of Burngreave.
A number of people have been arrested in connection with his death but nobody has been charged.
In addition, a 19-year-old man was stabbed on City Road on Monday.
None of the incidents are believed by police to be linked at this stage.
Detectives have also been dealing with another murder inquiry this week.
Martin Johnson, aged 19, of Leighton Road, Gleadless, was charged with murder last night following the death of little Erin Emilia Rain Tomkins.
A post mortem examination revealed the toddler, who would have turned two-years-old next month, died of severe head injuries.
Johnson appeared at Sheffield Magistrates Court today and was remanded into custody until his next appearance.
READ MORE: First video from scene of major incident on Sheffield estate
Police said they may now step up the use of stop and search powers following the wave of knife crime.
Officers are also visiting schools in the area today as they continue to step up their efforts to gather vital information.
*Anyone with information is asked to call South Yorkshire Police on 101 or Crimestoppers on 0800 555 111, quoting incident number 829 of May 24.