Child 44 is to much Hollywood, to much dramatized with too much cliches.
The 'actual story' about the murders came much too short and obviously only there to glue together the dramatization.
So everything we know from other movies all too well:
Don't be surprised to not find a lot in the list about the murder story, it was basically non-existing and replaceable with any other possible plot without changing the movie.
- kid in misery get saved and becomes hero of the nation
- hero is good at heart, thus will be let down
- hero fights against all odds
- in course of his search for truth he finds true love
- super-bad villain on personal vendata against the hero
- bad government institution and organization to fight against
- some pointless actio scenes
- show down villain against hero, and guess who wins
- happy end, villain dead, regime broken, murder found
Don't be surprised to not find a lot in the list about the murder story, it was basically non-existing and replaceable with any other possible plot without changing the movie.