The family of Harley Watson said they are “devastated” after the death of their “good, kind, helpful and lovely boy” in a hit-and-run crash.
Harley, 12, died in hospital after a vehicle ploughed into children who were leaving Debden Park High School, in Loughton, Essex, at 3.20pm on Monday.
Murder probe detectives believe the suspect may have planned a similar attack nearby moments earlier after they received reports of a car mounting the pavement near Roding Valley High School in Loughton at around 3.10pm.
Harley died in hospital from his injuries and six others – including five children – were also hurt in the crash on Willingale Road.
A 51-year-old man remains in police custody on suspicion of murder, attempted murder and other motoring offences.
In a short statement released through Essex Police, Harley’s family said: “We are so devastated by what has happened.
“Harley was a good, kind, helpful and lovely boy.
“We would like to thank everyone for their kind wishes and concern. However as a family we would like people to respect our privacy and allow us to grieve in peace.”
Scores of well-wishers have begun donating to a GoFundMe.com fundraising page in his memory, which has so far raised more than £30,000.
The force said on Tuesday it had “voluntarily referred itself to the Independent Office for Police Conduct (IOPC) based on previous contact between the force and a 51-year-old man arrested”, but said it was unable to give further details.
Discussing the second reported incident, Detective Chief Inspector Rob Kirby said: “The incident near Roding Valley High School, believed to have happened in Brook Road, was reported to us after it became widely known we were dealing with a serious collision in Willingale Road.
“Our investigations have led us to establish that there may be connections between that incident and the one which has led us to establish a murder investigation.
“I am appealing for anyone who witnessed that incident to contact my team. I would also like to hear from anyone who saw a silver Ford Ka travelling through Loughton between 2.40pm and 3.45pm yesterday to contact us, particularly if you have any CCTV or dash cam footage.”
Mr Kirby said the suspect was arrested in a vehicle in the car park of the Merry Fiddler pub in Fiddlers Hamlet at 11pm on Monday, and appealed for anyone with information or dash cam footage to contact police.
The man is being held on suspicion of murder, six counts of attempted murder and one of causing death by dangerous driving.
He is also accused of six offences of causing serious injury by driving, failing to stop at the scene of a collision and driving without insurance.
The arrest came after detectives appealed to find Loughton man Terry Glover in connection with the incident.
Two 15-year-old boys, a 13-year-old boy, a 16-year-old girl, a 12-year-old boy and a 23-year-old woman were left injured after the crash, Essex Police said.
The Rector of Loughton, Reverend Chris Davies, spent Tuesday morning at Harley’s school, as tearful parents and pupils laid dozens of floral bouquets near the entrance.
One, from a friend named Edith, said: “Dear Harley, I will miss you so much! Forever be in our hearts. Fly high.”
A football inscribed with handwritten messages including “sleep tight little man”, and “little man with a big heart” was also left in tribute.