Ball first became a police officer in 1987 as part of the Metropolitan Police, rising to the rank of
Operational Command Unit Commander in 2007 and remaining with them until 2010. She then transferred to become
Thames Valley Police Assistant Chief Constable, leading on Crime and Criminal Justice, and remained there for two years before returning to the Met as
Deputy Assistant Commissioner for Territorial Policing. She is the current trustee of the government-funded charity
Police Now. In March 2019, Ball chaired a disciplinary hearing of PC Terry Malka, convicted of outraging public decency by masturbating while traveling on a train, which decided to issue a final written warning rather than sacking him. As of February 2023, Malka was still serving with the force; this is being reviewed by the Metropolitan Police as part of an internal review into historic sex allegations. In December 2021, after a coroner's hearing into the 2014–15 murders by
Stephen Port, Ball admitted that "a number of recent events" had damaged trust in the Metropolitan Police. Later that month 2021 Ball chaired a misconduct panel which dismissed Jamie Rayner, a police constable already jailed for assaulting and strangling his partner during a 'controlling and coercive' relationship. After the activist Kate Wilson won £229,471 civil damages from the Metropolitan Police in January 2022 for being deceived into a sexual relationship with an
undercover police officer, Ball acknowledged the "gravity of the judgment" and that the police had breached Wilson's human rights. Following the resignation of the incumbent
Commissioner of the Metropolitan Police in April 2022,
Stephen House has acted as Commissioner and while Ball has acted as Deputy Commissioner while the
Home Office and
Mayor of London recruit a permanent replacement. In August 2022 she announced her intention to retire in October that year. == Honours ==