The problem is that police are being involved in the job of social workers. I guess it would be an acceptable and useful system if:

- Police had write-only access to the database.

- Police had no involvement in interventions.

- Anyone was able to fill out a form and get their data purged.

- Everyone in the database could easily discover it.

Basically, separate law enforcement and social work. And enforce strict data souvereignity.

The next problem is that it blurs the line between 'client' and 'suspect'.