Do the research. The times anything like that has come up, the Congress has decided that they don't have the right to do it.
The murder thing wouldn't wash anyway; it's criminal.
Do you not remember all the discussion when the case went to the Supreme Court about whether Clinton COULD be sued while in office?
He lost that suit, i.e., was found guilty and he was NOT impeached for that because it didn't happen while he was in office.
That was a civil suit. In any event, the "can't" bit was just a conclusion. I don't think it was grounded in anything.
Impeachment is a serious matter for Congress. They will only Impeach someone if they have good reason to. Note the number of times it has happened: 2.