In one recorded 911 call, a caller can be heard saying: "Some girl is getting her a-- beat upstairs."
In September, the then-Carolina Panthers defensive end agreed to be placed on the commissioner's exempt list, which suspended him from playing, as he and his lawyers appealed the court decision.
The charges against Hardy were dropped in February when Holder failed to show up for the hearing. According to ESPN, Holder and Hardy reportedly reached a civil settlement.
Hardy became a free agent in March but no team signed him. ABC News' attempts to reach Hardy were not successful.
The Cowboys signed the All-Pro defensive end Wednesday to a one-year deal worth up to more than $13 million Wednesday, after owner Jerry Jones said the team had spent weeks investigating him.
"Our organization understands the very serious nature of domestic violence in our society and in our league," Jones said. "We know that Greg has a firm understanding of those issues as well."
But critics aren't happy he was signed.
"Is there no line you [Cowboys] won't cross? Is there no crime you won't accept," said Dale Hansen, an outspoken sports anchor at ABC News affiliate WFAA-TV. "Now you can beat a woman and play with a star on your helmet."
As the Cowboys announced the deal, thousands gathered in Dallas for a Crimes Against Women conference.
"I'm afraid this is taking a huge step backwards," said Jan Langbein of the Genesis Women's Shelter. "If it isn't good enough for the Ravens, or Carolina, I can't imagine it's good enough for Dallas."