A police force which was investigating alleged assaults by a triple killer weeks before the Nottingham attacks has referred itself to the watchdog.
Barnaby Webber and Grace O'Malley-Kumar, both 19, were fatally stabbed on 13 June along with Ian Coates, 65.
Valdo Calocane was given a hospital order for the killings on Thursday.
About five weeks before the attacks, he started working in a warehouse in Kegworth, Leicestershire, where he was accused of attacking two employees.
The Independent Office for Police Conduct (IOPC) said it was assessing if any further action was required after the referral by Leicestershire Police, which related to an incident on 5 May 2023.
Further information from the force was requested by the watchdog after Calocane's sentencing at Nottingham Crown Court.
The force said no-one was seriously hurt in the factory assault and Calocane had reportedly been escorted off site by security before police arrived.
The IOPC also said it had contacted Nottinghamshire Police following the court hearing, asking for more information.
A spokesperson for the watchdog said: "In relation to a warrant being issued for Mr Calocane's arrest in 2022, Nottinghamshire Police provided us with information about that shortly after the tragic events of June 13 2023.
"We decided it did not meet our referral criteria because the contact had not been recent and no conduct issues were identified for any individual officer.
"Nottinghamshire Police subsequently carried out an internal review of matters linked to the warrant and we have now also requested details of that learning exercise, in case there are any issues that would require our involvement."
'Time will tell'
The families of the three victims met with Prime Minister Rishi Sunak at Downing Street on Monday, as well as Home Secretary James Cleverly and Health Secretary Victoria Atkins.
Speaking outside No 10, Emma Webber, Barnaby's mum, said the families "feel listened to".
Dr Sanjoy Kumar, Grace's father, said: "Time will tell. I think we need to just see what comes out initially.
"We've always been in this because we want improvements to be made.
"Our children, unfortunately, won't come back but we want people to be held accountable for what has gone wrong."
The families said that, during the meeting, the Prime Minister did not rule out an inquiry into the Nottingham attacks.
Mr Coates' son, James added: "It doesn't matter how long it takes as long as it's done properly - it has to be deep, it has to be detailed, it has to be independent.
"So we can get results, and everyone else can get results, because at the end of the day there's a lot more people out there."
The families also met with Labour leader Sir Keir Starmer, who they said was "very supportive" of their calls for a public inquiry.
Speaking to BBC Breakfast earlier on Monday, Mr Webber's mother Emma called for a public inquiry.
She said a special review which has been ordered into Nottinghamshire Healthcare Foundation NHS Trust, which treated Calocane, would just be "a toe in the water".
"It needs to be much more than reviewing the mental health failings and services in Nottingham," she said.
"Also, the failings of the police to investigate and act accordingly up to the attacks and also the investigation of the case we've got real concerns about, and the way we've been managed by the CPS [Crown Prosecution Service] and of course, we're really unhappy with the outcome from last week."