No system. Trust me NO SYSTEM!
This novel reminds me of anime/manga/lightnovel where mc defeats the villain, only to later find out that there is an evil organization behind him, and later it turns out that there is another, even more evil organization behind the evil organization.
Overall MC have only one case through whole novel, at least it feels that way. MC is police detective and police is always late and mc perfectly preserves this tradition. Always step late and whole novel is like that. It is interesting read but at the same time it is exhausting. Sometimes simple police procedure can point shortest way to the clue: like dude without face lying on the ground have tattoos all over the body and none one have enough brain power to check out if he is from known gang (usa). another case: there is a suspect, no, 100% confirmed killer, the police have a real name. What should be done? the right thing to do is to raise all information about him. INCLUDING cash flows. They were running around for 2 days, in the end mc decided to check the bank account... found a clue...