Ricky Morgan set upon a complete stranger in an unprovoked attack on a train in central London last summer.
In the male-dominated world of firefighting, Chloé Cassar wants other young women to consider it as a career.
By Daniel Sandford
BBC News home affairs correspondent
The Metropolitan Police's Helen Ball says the Partygate investigation, with a full-time team of 12 detectives supported by others, cost £460,000.
The Labour leader says the prime minister is responsible for the culture that led to 126 fines over lockdown parties in Downing Street.