A Duty Solicitor is A Criminal Solicitor - independent of the Police or the Crown Prosecution Service who provides free legal advice and representation at Police Stations or Magistrates Court to people suspected or charged with a a criminal offence. 2. Usually works for a Criminal Solicitor's firm within the local area. The firm will be contracted by the Legal Aid Agency to provide those services at local courts and police stations at times and dates specified on a duty rota.