Two police constables have been dismissed from the Metropolitan Police for gross misconduct following the death of a 17-year-old youth who was punched at a party.
Pc Claire Derbyshire and Pc Peter Cruise "failed to ascertain the victim was 17-years old and that other young men were at the scene who had been drinking with juveniles," the force said.
Both officers "knowingly made misleading and inaccurate reports of the outcome," police added on Thursday.
George Verrier died in September 2013 - the day after a punch caused him to fall to the ground and hit his head on the road in Bromley, south-east London.
The "healthy, funny and intelligent young man" was briefly unconscious before going home with a friend and sleeping, but was taken to hospital when he could not be roused the next day.
A post-mortem examination showed that the impact with the road had caused a skull fracture and bleeding from an injured artery.
It was also found that "both officers conducted no or insufficient inquiries regarding the identities or particulars of the victims, suspect and witnesses".
Deputy Assistant Commissioner Fiona Taylor said: "George's death must have been heart-breaking for his family.
"At the very point George needed the Metropolitan Police Service, these officers let him down causing his family even more distress.
"Their actions clearly fell far below the standard of professional behaviour we expect from our officers and they failed to assist someone who was clearly in need of their help."
The pair had faced a public misconduct hearing for breach of standards of professional behaviour, relating to honesty and integrity, duties and responsibilities and discreditable conduct.
The panel found cases against both officers to be proven following a four-day hearing.
George, an apprentice electrician from Bromley, had been to a party at a house in Blenheim Road and was assaulted in the early hours of Sunday September 1 2013.
Following the incident, the Met made a voluntary referral to the Independent Police Complaints Commission (IPCC), leading to the force carrying out a local investigation into contact between officers and the teenager.
Four police constables based at Bromley borough were interviewed by the Directorate of Professional Standards (DPS), with one police constable receiving local management action and one local management advice, while Pc Derbyshire and Pc Cruise faced the misconduct board.
Ben Hayes, 20, was sentenced to four and a half years in a young offender institution for George's manslaughter in October 2014.
He won a nine-month cut in his sentence at the Court of Appeal in London in February 2015 after he was described as being of "exemplary character".
The court heard the teenagers had attended the same 16th birthday party, which had passed without incident and both had drunk only moderately.
But afterwards, a "pumped up and angry" Hayes confronted someone he thought had assaulted a friend, and shouted at George when he intervened as a peacemaker, before punching him on the left side of the face.