this spouse check thing is very very common atleast in Pakistan in the case of arranged marriages...
recently someone we know checked with the local thana of the prospective's locality checking if there was ever any case against that person or their parents...
ppl do checks of the whole khandaan, their property, their business dealings and what not...
ppl check if the person actually graduated with the degree from the college they claim...
all this kinda stuff...
at the end of the day i think a lot has got to do with "kismat"...you can get married to the "cleanest" person but if Allah has written something bad in your fate than you can't avert that...and sometimes if you marry a so called "criminal" but Allah has written that (s)he will become a good spouse for you and your family then nothing can change that too...
some ppl even lie though (happenned to a relative of mine recently and it was a rude shock to everyone in our family)...the susraalis lied about their property and the guy...it was really a sad situation and caused a lot of pain to my cousin...some ppl dont disclose diseases their children have, like TB, and get them married off...this has also happenned to someone in my family...
there's all sorts of ppl in this world with all kinds of weird thinkings...
if you've known someone lets say in college for four or five years and don't know too much abt their khandaan but know their personality and present habits.... thats a different thing...but if you've only just met someone and haven't known them for sometime on a personal level then its a given that you don't know a lot about them...assumptions can be false and should never be made abt anyone...
my personal belief is that its the present that counts not the past...but some part of the past can play a role into the present and the future and should be taken into account...like what if a person has kids from a past marriage or even a wife? obviously that's going to affect the present and the future...what if the person has a past criminal record like if they're a political refugee or something?
im not saying dont marry such a person but jus saying be aware of it and prepare urself to deal with it coz it could be a surprise if such things are discovered after marriage..
emotions should never come into play in this entire matter and one should approach marriage very practically, not with some dreamy eyed indian movie type notion of "love" or whatever, one should never rush into making any commitment...
to be honest i think a background check must be made but maybe the other person should not be told about it, and if something comes up that seems strange then the other person should be asked abt it mildly... its not abt betrayal of trust ... if there's no commitment till that point then there's nothing wrong with checking the person's background ... and there should be no commitment, emotional or official, until all such practical details have been sorted... one should commit only when they are mentally at peace about everything ...
lekin ofcourse...in the end...theres only so much these things help with...at the end of the day its all in Allah swt's hands and a lot of it is just your fate :)