Caller from this number claimed to be special investigator with IRS. Abruptly hung up when questioned.

he said my husband or his lawyer on record should call him because of a tax evaction

caller left message saying to return call about problem with your income tax. Called back and hung up twice. Number is calling from private residence on Nicasio Valley Road, in mtns outside San Francisco.
Reported to FTC. btw, IRS does not make phone calls to you, everything done by mail.

my customer received a phone call saying that a warrant for her arrest would be issued the next day

Oh God--This company is the worst and the person I spoke to can't even speak english and is so rude.  He gave the name of Andrew, and the phone number 415-662-8528, stating he is local (NOT).  He asked for an employee here and repeatedly called back 3 times.  He said he is with the IRS and gave us a reference number.
   I called the local number and what it does is it routes the calls, I presume overseas for some type of scam.