text: Sue Sim was the first woman to lead the force and led the hunt for murderer Raoul Moat in 2010.
  Last month Northumbria Police and Crime Commissioner Vera Baird launched an investigation into Ms Sim over alleged rudeness to staff.
  Ms Sim is retiring on 3 June to spend more time with her family to "make up for the sacrifices" they made.
  She joined Merseyside Police in 1985, progressing through the ranks before moving to Northumbria in 2004.
  Ms Sim said the hunt for Moat following the murder of Christopher Brown and shooting of one of her officers, PC David Rathband, was one of the biggest challenges she faced.
  She said: "That was the largest manhunt the country has seen for 44 years. I spent my time out and about reassuring the public and responding to their questions.
  "I am immensely proud of my officers and staff who went about their roles fully aware of the threats against them, but determined to support the public."
  She has also overseen savings of Â£117m since 2010 and was at the helm as Northumbria Police reopened no crime rape reports following an audit.
  Ms Baird's office said the misconduct investigation will continue but admitted if the complaints against her were upheld, Ms Sim's retirement would mean any sanctions, such as a written warning, would have no impact.
  Ms Baird said: "Sue has brought passion and enthusiasm to her role and leaves at a time when Northumbria is one of the highest performing forces in the country."
target: The chief constable of Northumbria Police will retire after 30 years of service, it has been announced.