The scourge of London moped gangs reached disturbing heights last week when a police officer stopping a pair of riders was threatened with a knife and had his motorbike tyres slashed.
The officer had been on a marked police motorbike when he spotted the moped driver and his pillion passenger acting suspiciously in Benwell Road, Holloway.
The officer signalled for them to stop but the moped made off, eventually stopping just over a mile away in Sunnyside Road in Crouch End.
Police say the pillion passenger then dismounted from the bike, threatened the officer with a large knife and used the weapon to slash the officer's motorbike tyres.
Both the rider and the pillion passenger made an escape on their moped. The officer was not injured.
The incident happened on Wednesday (22 November) at around 2.30pm. Scotland Yard has appealed for anyone with information to come forward, especially motorists with dashcams who were driving in the area at the time of the incident.
Both the driver and the accomplice are described as male, aged between 18 and 22 years old, and were wearing dark clothing and black helmets. There have been no arrests.
Detective Inspector Greg Coates, of the Met Police, said: "These men are clearly dangerous and need to be arrested. We are keen to speak to anyone who may have witnessed this incident or has any information.
"In particular we would like to hear from anyone who was in this area at the time and has dashcam footage. If you were in the vicinity of either in Benwell Road, Hornsey Road or Sunnyside Road on Wednesday afternoon, please call police; your information could be vital."
The latest incident raises further questions over how Scotland Yard aims to tackle a spike in moped-enabled crime in the capital.
The Met Police recorded 16,158 thefts by criminals on mopeds in the 12 months to June, more than three times the figures from the previous year.
The crime stats include moped muggings of pedestrians, smash and grab raids on businesses, stabbings, acid attacks and thefts of other mopeds.
Home Secretary Amber Rudd recently told a police summit the government was reviewing guidelines for police pursuits.
The announcement came amid complaints moped criminals are currently able to make an easy getaway because officers were too scared of chasing them, fearing the pursuit will end in a crash and they will be hauled before a court.
Any witnesses or anyone with any information about the incident is asked to call police on 101 or contact via Twitter @MetCC. To give information anonymously contact Crimestoppers on 0800 555 111 or online at crimestoppers-uk.org.