take the fall for sb

to take the fall for somebody (to accept all of the negative consequences for something you did not do, to accept the blame for something you did not do, usually to help the person who is responsible for it) — взять вину за что-л. на себя (for sth); взять чью-л. вину на себя, прикрыть кого-л. (for sb)

Example 1: Не took the fall for the robbery.

Example 2: When my boss got around to questioning me if it was Kelly who lost the report, I took the fall for her and pretended I did it.

see also
[stick one's neck out]
[put one's head on the block]
[put one's neck on the line]

cf.:
[fall guy]
[take the rap]