It's not a series but I watched the late 1980s documentary "Fourteen Days in May" on BBC Iplayer based on Louis Theroux's recommendations of must watch documentaries that had influenced him.
It may not be for everyone but I found it to be a very powerful and moving film showing the building tension in the days and hours before an apparently innocent man's scheduled execution.
https://www.bbc.co.uk/iplayer/episod...en-days-in-may