For some people maybe it depends on the crime. For the people in this experiment they were willing to help their friend without knowing what had happened.
Four people were secretly filmed to see how they would react when asked to hide incriminating evidence by a close friend. All they were told by their friend over the phone was they got into a bit of trouble the night before and needed them to go to an apartment and get a bloody shirt from the kitchen sink and get it out of there and fast.
Even when the police show up the friends act like they don’t know anything and cover for them.