Anthony Quinn Warner sent information to friends days before the Christmas blast in downtown Nashville, according to authorities.
Richard Holzer, arrested earlier this month, faces a maximum prison sentence of 50 years.
Paul Rosenfeld intended the blast on Washington's National Mall to draw attention to "sortition," an ancient political ideology, authorities said.
Leader Kim Jong Un inspected the bomb, which can be mounted to an intercontinental ballistic missile.
The Pentagon released aerial footage of their April 13 MOAB GBU-43/B strike on ISIS cave and tunnel systems in Afghanistan.
As reporters speculate whether or not President Trump knew about the use of a "Mother Of All Bombs" on ISIS in Afghanistan, Sean Spicer declines to answer questions.
Two Somali soldiers were killed and five others were injured by the explosion.
“I was glad I was able to do something to keep other people from being hurt.”
There’s a reason presidents try not to guess motives behind violent acts before the facts roll in.