I thought she said her name was "Officer Sherman Cruz" of IRS Criminal investigations, but caller ID showed the phone as being listed to "Shawn Marsh".
Just picked up a similar message. It sounded recorded, with the "caller" identifying herself as Ofcr. Shirley Cruz with the Internal Revenue Service investigative division of the Federal Bureau of Investigation, Yikes! So the first thing I did was an internet search of the number she left: 202-241-7566, and, thankfully, found myself here. Very suspicious.