Assistant U.S. Attorney Chris Niewoehner is taking the questioning into Monk's fund-raising activities with the Friends of Blagojevich campaign.
Monk got involved with fund-raising for Blagojevich during the 2002 election cycle. That's around the same time that Monk met former Blagojevich fund-raiser Chris Kelly.
"He was a contributor, a big contributor to Rod and was starting to raise some money from other people," Monk said of Kelly, who owned a roofing company.
There was a brief, surreal moment when prosecutors posted a giant photo of Kelly on an overhead screen for Monk to identify.
Blagojevich looked up at the photo, who is deceased after taking his own life last year, and back to his old friend Lon Monk, who is on the stand.
Judge James Zagel has said that jurors may not hear about Kelly's suicide.
Niewoehner asked Monk about his relationship with Kelly.
"We mostly had meals together, or coffee," Monk said. "We may have gone to a ballgame."
Kelly and Blagojevich, too, were "close," Monk said.