On the 8th January 2018, the Independent Office for Police Conduct (IOPC) was launched, replacing the Independent Police Complaints Commission (IPCC). The IOPC oversees the police complaints system in England and Wales. In addition to investigating the most serious matters, and setting the standards by which the police should handle complaints, the IOPC uses the learning from its work to influence changes in policing. Since 2007, the IOPC (as the IPCC) has published a 'Learning the Lessons' bulletin, which is intended to challenge police to think "Could it happen here?".
The bulletin includes learning on a range of police activity, including missing persons. In order to assist partners, the case studies and learning from those related to missing persons, and concern for safety incidents, has been collated into a single document, which can be downloaded below.
More details about the IOPC, and how to make a complaint, can be found on their website.