Federal securities authorities will take a second run at trying to prove to a Denver jury that one-time oil executive Roger Parker a decade ago leaked insider information to his buddies so they could profit from it. Mark T. Osler, The Denver PostDelta Petroleum’s former chairman and CEO Roger Parker, photographed in the boardroom of the downtown Denver office on March 5, 2008. The new trial is set to begin Tuesday before U.S. District Judge John Kane — exactly five years from the day the U.S. Securities and Exchange Commission levied its allegations. The SEC maintains the 56-year-old former chief executive of Delta Petroleum told at least two friends — who then told others — that late-billionaire Kirk Kerkorian in 2007 was poised to drop $684 million into the company, an investment that surely would make the company’s stock price climb once it was announced. It did, by about 19 percent, and resulted in illicit profits topping $1.5 million to those who bought-in before the January 2008 announcement was made. Parker, however, never personally traded on any Delta stock at the time and said the tips were merely idle chatter among friends. But government attorneys in September had a hard time proving their case to a federal district court jury following a two-week trial, which ended with a hung jury after a week of deliberations, leaving the SEC little choice but to start over. The witness list has included billionaire George Solich, high-powered attorney Norm Brownstein, Kerkorian confidant and executive Dan Taylor, and oilman John Wallace, who is married to Beth Bowlen, daughter of Denver Broncos owner Pat Bowlen. Along with Kerkorian, who died in June 2015, other key figures now dead include Edward Michael “Tiger” Davis, a former chauffeur who entered the oil-and-gas business after marrying former Denver Post owner Helen Bonfils. Davis, who died in September 2016, was a Las Vegas resident who had done business with Delta as far back as 2003 and introduced Parker to Kerkorian. Though Parker’s team of lawyers has pointed to the mistrial as a reason to dismiss the civil lawsuit, federal lawyers appear determined to prove the now-bankrupt oilman somehow profited from