I got the same call and I work for the IRS, Reported it to the Treasury Inspector, You can file a report at IRS.gov, type scams in the search box and fill out the form. This will help track down the scammers
This is the second call for me. The same as others - clearly a scam- The federal govenment is not going to call you on a Friday night after 5PM- also did not give names, case numbers etc., Just said that there was going to be a law suite etc.
The first caller used the words US Treasury and Magistrate- Very strange.