The alignment is pointless/alignment is perfect debate has a fun little wrench.. Dexter Morgan is a strict Cap L Lawful Cap G Good Paladin. He does good finding the right bad guy at work then in his spare time goes above & beyond searching out evil people that he not only checks background in the DB but goes further by watching them to make sure they are still going to ping evil with detect evil. He does all of that while minimizing the evil doer's suffering and following the code given to him by a higher power (police chief Harry). Even when his own safety was at risk from Doakes Dexter still didn't kill him.
When lawful good includes dexter morgan it's useless
When lawful good includes dexter morgan it's useless