Kvon R. Smith, 20, was arrested Tuesday for allegedly bringing explosive materials into the Statehouse, the Milwaukee Journal Sentinel reported.
Police called in a bomb squad to deal with Smith's backpack after learning he posted a threat on his Facebook page early that morning.
The post was a video titled "haha" in which a man is heard saying, "So check it out. I made a few Molotov cocktails. I still have some stuff to add... This is for today. We'll see what they'll have to say when I bring it to the Capitol."
He continues, "If they want peace, bring it to Milwaukee. If they want peace, I want my money."
Bottles of non-explosive and non-flammable liquids were found in Smith's backpack, Madison Fire Department Division Chief Lance Langer said.
One bottle contained motor oil, another contained clear water and chalk, and the third contained rubbing alcohol, he said.
Gov. Scott Walker praised the "tremendous job" of Capitol police and local law enforcement in responding to the incident.
"I called two of the officers today and thanked them for the professional work, because it was a credible threat. It could have ended up very dangerous -- it did not thankfully. It was good work all around," Walker said.