The misdemeanor charge stemmed from an alleged physical altercation the former Michigan standout had with his girlfriend in Ann Arbor in March. Police at the time told NFL.com they determined Lewis was the aggressor in the alleged assault after two interviews with his girlfriend.
Lewis, 21, pleaded not guilty to the original domestic violence charge on March 16. Under Michigan law, he faced a maximum of 93 days in jail and a fine of $500 if he was convicted.
In a statement obtained by NFL Network Insider Ian Rapoport, Lewis' agent, Kevin Poston, wrote: "We thought all long that Jourdan would be totally exonerated and he was. Justice was served."
Lewis missed the first two days of Cowboys training camp in Oxnard, California, to attend his trial.
"These are stressful, trying events and I think [Lewis] is happy it's over and how it came to be over," Shea said.
Since the alleged incident occurred before he was selected by the Cowboys in the third round of this year's draft, he is not subject to potential NFL discipline under the league's personal conduct policy.
Cowboys owner Jerry Jones said after Dallas drafted him that the team thoroughly looked at his situation before deciding to draft him.
"We were satisfied that we would be OK there," Jones said then.