@DrSuzanne A lot probably have the mindset that refusal to talk makes them look guilty. Which is kinda true if they've spent their lives normalizing a worldview where cops are trustworthy and benevolent.
This is one way in which having a preexisting, widely expressed ACAB mindset serves folks' self-interest. It's not sus refusing to talk to cops if you've been shouting ACAB visibly and publicly for a long time.