Mystery Dem-backed super PAC Highway 31 spent millions in Alabama race

Mystery Dem-backed super PAC Highway 31 spent millions in Alabama race

A mysterious super PAC poured millions into the special Alabama Senate race between Doug Jones and Roy Moore, and that group was reportedly funded heavily by the Democratic Senate Majority PAC.

According to Senate Majority PAC spokesman Chris Hayden, the Democratic Senate Majority PAC spent $4 million and "predominantly funded" super PAC Highway 31 -- a group that sent out mailings and ran advertisements against Republican candidate Roy Moore.

Highway 31 did not have to disclose the payments during the campaign due to payment schedules, causing Moore's campaign to criticize the group as "shadowy."

The Senate Majority PAC spent about $6 million total in the Alabama race.

In a stunning upset, Doug Jones defeated Roy Moore on Dec. 12 -- making him the first Democrat to serve Alabama constituents in the Senate in 20 years. Jones is a former U.S. attorney who has previously prosecuted Ku Klux Klan members.

RELATED: A look back at Roy Moore on Alabama election day