I know what this word really means but I cannot help to think that ignorant also means he ignores his surrounding or the consequences of his actions. “He was ignorant, unwilling to warn the police about what has been happening next door for years” for example.
Can anyone tell me the word I am looking for? Or is it too broad to find a suitable adjective?
I don’t know about a single word, but what you’re describing sounds like willful ignorance or willful blindness, described by Wiktionary as
A decision in bad faith to avoid becoming informed about something so
as to avoid having to make undesirable decisions that such information