The police watchdog is investigating whether a man accused of murdering a teenager could have been arrested 12 days before the alleged killing.
Imran Akhtar Hussain, 26, from Bracknell in Berkshire has been charged with killing 18-year-old Kieran Crump Raiswell on January 16 this year.
The teenager, who was about to start a degree at Sheffield University, was stabbed in the chest while walking along the street in Whalley Range, Manchester.
He was given first aid by a passing fire crew but his injuries proved too severe and he died in hospital.
Twelve days earlier, it is alleged, Hussain punched a stranger in the face in Nottingham, leaving the man, Paul Kershaw, with concussion and bruising.
Nottinghamshire Police referred the case to the Independent Police Complaints Commission (IPCC), which is investigating whether the force could have arrested Hussain before the alleged murder.
IPCC Commissioner Sarah Green said: “We will be looking at the quality and thoroughness of the Nottinghamshire Police investigation into the assault, and whether there was any reasonable opportunity to apprehend the suspect earlier.”
Hussain is facing charges of murder and common assault.