I think this is more than what has been suggested; this seems to be about a German "Feststellungsklage" and the resuting judgment
(which is a much stronger statement)

If would use one of the usual phrases (the court finds as follows...) or use a literal translation in quotes and add (Feststellung) - any lawyer worth his/her salt will then immediately know what that means (legally).

This might not be the case with the other suggestions, I think - and it's definitely not a mutual agreement or merely an assertion - this is the final court decision