A major overhaul of the police complaints system in England and Wales begins on Monday with the launch of a new watchdog.
The Independent Police Complaints Commission (IPCC) is being replaced by the Independent Office for Police Conduct (IOPC) as part of a shake-up announced by Theresa May as home secretary.
Ministers say the changes will bring about speedier decision-making and greater accountability to the public.
New powers, which will be introduced in the coming year, will mean the IOPC can initiate its own investigations without relying on a force to record and refer a particular case.
The Home Office said the IOPC, like the IPCC before it, would continue to investigate the most serious and sensitive matters involving the police, including deaths and serious injuries as well as matters such as allegations of corruption.
Policing Minister Nick Hurd said: "We are absolutely determined to make the police complaints and discipline systems simpler and more transparent for the benefit of the public.
"We want confidence in policing to continue to grow and be underpinned by the vital role the reformed IOPC will play.
"It will provide powerful scrutiny for policing, with new powers to begin investigations when they are deemed appropriate and be decisive in concluding cases."
Director general of the IOPC Michael Lockwood said: "Public confidence in policing is best served by robust and independent oversight.
"People need to know that when things go wrong, or serious allegations are made about police officers, they will be thoroughly investigated by a truly independent body.
"That's the role of the IOPC; it's crucial work, and I'm proud to be a part of it."
The IPCC became operational in April 2004.