In the 1980s, federal prosecutors going after mob-controlled labor unions investigated a series of dealings between organized crime and real estate developers in the New York and New Jersey area.

One developer they were particularly interested in was singularly uncooperative in discussing what appeared to be sweetheart deals with the mob. That developer was Donald Trump. 

Attorney Kenneth McCallion was one of the federal prosecutors involved in that investigation. He says there appeared to be a sweetheart deal between the Teamsters Local 282 and Trump, where Trump would get a promise of cooperation from organized labor—including breaking up any strikes by minority workers—in exchange for no-show jobs, a lucrative concrete contract and a luxury apartment for the union president's girlfriend.

"After we indicted them, the Teamster leaders called a citywide strike, but there were two job sites they exempted from that. One was Trump Tower and the other was Trump Plaza," McCallion said.

Yet despite this, Trump was never prosecuted. 

"Even though Donald Trump lied to law enforcement about his relationship and lying to federal agents is a federal crime, he basically got a pass at that point," he said.

McCallio, who recently wrote the book, The Essential Guide to Donald Trump, says the Republican candidate for president has continued to enjoy a comfortable relationship with organized crime.