In countries where it's clear that police officers and government officials are performing illegal arrests & detentions, tracking these individuals is arguably as important as tracking the victims themselves. The vast majority of victims of unlawful detentions will be caught off-guard, making it difficult to prepare each of them. However, the detainers themselves are likely repeat offenders if not part of a systematic program of unlawful detentions. Shedding light on who these people are and the details of their whereabouts may be a critical piece of the social and political pressure needed to keep their illegal actions in check.
When it comes to unlawful detention it seems there are two categories of countries that commit offenses: those that maintain an official stance against it, and those that incorporate it to some degree in their method of government, whether or not acknowledged.
Technologies that would likely work in the former type of country for monitoring the whereabouts of officials could be implemented from the top down:
Much more difficult, of course, is devising a strategy for monitoring these officials in countries that do not denounce unlawful detention. However, there are still technologies that could begin to illuminate places, vehicles, and individuals that are frequently a part of unlawful detentions: