The man arrested on suspicion of murdering Barnaby Webber, Grace O’Malley-Kumar and Ian Coates in Nottingham has been named as Valdo Amissão Mendes Calocane.
Nineteen-year-old students Mr Webber and Ms O’Malley-Kumar and school caretaker Mr Coates, 65, were stabbed in the early hours of Tuesday.
The suspect, 31, was subsequently arrested and remains in custody.
Officers have been granted a 36-hour extension to continue questioning him.
He graduated in mechanical engineering from the University of Nottingham in 2022.
The dual Guinea-Bissau/Portuguese national had settled status in the UK through his Portuguese citizenship.
Mr Webber and Ms O’Malley-Kumar were attacked by a man with a knife in Ilkeston Road, shortly after 04:00 BST on Tuesday.
After this a man matching the suspect’s description attempted to get into a supported living complex in Mapperley Road, but was unable to gain entry.
Police believe shortly afterwards he attacked Mr Coates – who was found dead from knife injuries in nearby Magdala Road – and stole his van which was then used to hit pedestrians.
One of these was left in a critical condition, but a Nottingham University Hospitals (NUH) NHS Trust spokesman said he was now stable.
Mr Calocane was arrested at about 05:30 after police stopped a van in Maples Street.
Custody rules state police can hold people for up to 96 hours if they are accused of a more serious offence, such as murder, before they are charged or released.
People arrested under the Terrorism Act can be held without charge for up to 14 days.
Nottinghamshire Police said it was keeping an “open mind” about the motives for the attacks, and was working alongside counter-terrorism police, as would normally be the case for an incident like this.
Vigils for the victims were held at the University of Nottingham’s campus on Wednesday and in Nottingham city centre on Thursday.
Ms O’Malley-Kumar’s mother Sinead addressed the crowd in the city’s Old Market Square and urged them to be “kind to one another”.
“Look after each other, don’t have hate in your hearts. Say prayers for my baby girl,” she said.
Mr Coates’s son James also gave a speech, telling the crowd: “It feels like he touched a lot of hearts over the years, a lot more than we knew and assumed he had.
“It’s been really nice and heart-warming to see messages and people coming out to say how he was with them when they were younger.
“We are still dealing with what’s happened, we still haven’t taken it all in.
“Dad was an avid fisherman, he loved his family and he also loved his Forest.”
He ended his address with “You Reds!”, drawing cheers from the crowd, many of whom were wearing Nottingham Forest club colours at the family’s request.
England and Australia cricketers will also be wearing black armbands in tribute to the victims on day one of the first Ashes Test at Edgbaston.
Both Mr Webber and Ms O’Malley-Kumar had been keen and talented cricketers.
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