A 73-year-old woman has died in hospital after being bitten by a police dog that was searching for a suspect in her garden.
Irene Collins was attacked by the German shepherd last week at her home in Middlesbrough.
The Assistant Chief Constable of Cleveland Police, Sean White, said: "Members of Cleveland Police share the grief that is felt and we all wish to express our sincerest condolences to the family."
Mr White said the Independent Police Complaints Commission had been informed of the incident and would be deciding how to investigate what happened.
He said the force were "commited to learning any lessons" from the incident, but stressed that using dogs was "operationally important" to fighting crime and protecting the public.
The dog involved has been withdrawn from duty, while its handler is also receiving support, he added.