Five youths have been jailed for the murder of a teenager who was run down by a car before his attackers – including one wearing an electronic monitoring tag – chased him down and stabbed him to death on a London street.

Lord Promise Nkenda was stabbed 15 times on 14 February 2018 in Newham, east London, by a gang aged 14 to 17, in a suspected case of mistaken identity.

They carjacked the BMW earlier in the day. One of the group, Ephraim Idris, 17 at the time of the attack, was wearing an electronic monitoring tag after being convicted of “county lines” drug-dealing in Exeter, Devon.

It is believed the vicious attack may have been a case of mistaken identity as detectives could find nothing to connect the victim and his attackers.

Idris was sentenced to 16 years on Monday. Three other attackers were aged 17 at the time: Shemar Dawes and Ishad Abdille, who were sentenced to 18 years, and Anton Muir, jailed for 17 years. A fifth youth, who was 14 at the time and cannot be named for legal reasons, was sentenced to 14 years.

Nkenda, 17, who hoped to be a musician, was walking with two friends on the pavement when the group of five turned the stolen car into a weapon, the Old Bailey heard.

He was thrown up on to the bonnet but managed to get up and run as the youths burst out of the car and chased him armed with at least one knife. Nkenda was stabbed in the head, face, chest, upper arm and thigh, and died where he fell despite attempts by paramedics to save him.

The youths had stolen the BMW from a woman two hours earlier and, in a sign of how premeditated the attack was, donned latex gloves beforehand hoping not to leave fingerprints or DNA to connect them to the crime.

Sentencing the five teenagers, Judge Zoe Smith said: “You cornered him against a van and there he was stabbed. He had 15 separate stab wound injuries and a number of them were very deep wounds.

“In the final seconds of the attack, the CCTV shows that you, Mr Abdille, came from behind the van and you can be seen stabbing at Promise three or four times. Why this pedestrian was targeted is not known. The crown do not exclude this as being a case of mistaken identity.”

During the trial, Alan Kent QC, prosecuting, said: “There would appears to be a significant degree of planning or premeditation. They turned off their mobile handsets in order to avoid detection by cell site data.”

The murder caused devastation for the families left behind. Abdille’s mother, who has worked for nearly 20 years as a nurse saving lives in the NHS, was left distraught.

The victim’s brother, Patrick, said: “Promise died in a sustained and frenzied knife attack. He died alone and cold in the middle of the street. We never have got to say goodbye to him. We never got to tell him how much we loved and cared for him.

“Since the death of Promise, we have all become shadows of our former selves. We are devastated. We feel empty and numb, but most of all incredibly sad. A part of us all died with him, alone on that east London street. The impact of this day has had a lasting effect on us a family and individually.”

DCI David Whellams, who led the investigation, said: “The ages and determination of those involved – a boy who was 14 at the time of the attack and a group of other teenagers – is chilling. The calculated nature of this attack, where criminality like carjacking was just a means to an end, is also disturbing.”