Essex Police said in a statement that the 51-year-old, from Loughton, has also been arrested on six counts of attempted murder and one of causing death by dangerous driving.
He also faces charges including causing serious injury by driving, failing to stop at the scene of a collision and driving without insurance.
Four teenagers thought to be pupils at Debden Park High School in Loughton and a 23-year-old woman were also injured when the car ploughed into them.
Officers had begun a manhunt as they tried to trace a silver Ford Ka, with the registration LS08 OKW, which is believed to have been damaged in the crash in Willingale Road.
Head teacher Helen Gascoyne said the school had been ‘devastated’ by the death of one of its students and that pupils would be offered counselling on Tuesday.
Chief Superintendent Tracey Harman told reporters on Monday night: ‘We believe that the collision was deliberate and as such we have launched a murder investigation.
‘We are investigating whether or not this incident may have been connected with another incident nearby.’
Earlier, Ms Harman said searches had been carried out to try to locate Glover, as she appealed directly to him to come forward.
Police were called to the scene shortly after the end of the school day, at around 3.20pm on Monday.
East of England Ambulance Service sent 15 ambulances and 10 other vehicles, while three air ambulances were mobilised.
A 12-year-old boy was taken to hospital where he died.
Two 15-year-old boys, a 13-year-old boy, a 16-year-old girl and the 23-year-old woman were also hurt.
Essex Police said they were treated at the scene or in hospital, and their injuries were not believed to be life-changing or life-threatening.
Detective Chief Inspector Rob Kirby said: ‘This has been a truly shocking incident and my deepest sympathies are with all those involved.
‘I would like to thank the many members of the public who have called us with information and spoken to our officers, as well as those who provided crucial medical assistance at the scene.
‘I would urge anyone with information, dashcam footage, or who may have seen anything on social media that they think could be crucial to call us on 101 and quote incident number 726 of 2 December.’
Debden Park is a mixed academy school for pupils aged 11 to 18, which specialises in the performing arts and received a rating of "outstanding" in its most recent Ofsted inspection, according to its prospectus.
A statement from Ms Gascoyne said: ‘As a school and a community we are devastated to say that as a result of the incident in Willingale Road this afternoon, it is with great sadness that we must report that a 12-year-old student from our school has sadly died.
‘Our thoughts are with the family and all those affected. As a school we continue to work with the police supporting the ongoing investigation.
‘The school will be open tomorrow with a number of counsellors on hand to support our community.’
A police cordon remained in place along Willingale Road on Monday night manned by uniformed officers.
The cordon began metres from the entrance to the school, near the junction of Jessel Drive, and an officer was going door to door in the streets nearby.
Armed police could be seen outside a home on the corner of Newmans Lane and Hatfields in Loughton, where neighbours said Glover lived alone.
No lights were on in the property but two armed officers were stationed outside while a marked squad car was parked in the road.