Is there a word that means deliberately ignorant, choosing to ignore?

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 might prompt

An expression of the ostrich effect is bury one's head in the sand, hide one's head in the sand; have one's head in the sand:

Fig. to ignore or hide from obvious signs of danger.

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In this particular case the phrase in denial seems appropriate:

in a state of refusing to believe something that is true.

Mary was in denial about her illness and refused treatment.

You could say he's got a three wise monkeys attitude (speak, see, hear no evil)...

To ignore can conveys the concept of being deliberatly ignorant or choosing to ignore.

• To refuse to pay attention to; disregard.

• to refrain from noticing or recognizing: to ignore insulting remarks.

• he simply ignored what had been happening next door for years.

(TFD)