Joseph A. Jakubowski, 32, robbed a gun shop April 4 in Janesville, Wisconsin, according to the Rock County Sheriff's Office.
He allegedly stole several guns from the shop and escaped. About 30 minutes later, his abandoned car was found ablaze on a nearby street.
The same day he's accused of stealing the guns, Jakubowski sent a 161-page manifesto to the White House and left behind a video showing himself mailing it, according to Cmdr. Troy Knudson.
In a portion of the manifesto obtained by CNN affiliate WTMJ-TV
in Milwaukee, Jakubowski purportedly described the government as a "gang of terrorists."
He said he stole the guns because the system has "stolen my natural right to protect and defend life," WTMJ
"Priests and churches control the presidents and the banks ... ," he wrote, according to the affiliate. He also described health insurance and taxes as a way for the government to brainwash its citizens.
CNN has sought to verify the authenticity of the manifesto and get more details from the Rock County Sheriff's Office but hasn't heard back from the lead local agency in the investigation.
A law enforcement official close to the investigation confirmed the portion of manifesto as authentic, according to the affiliate.
Police have described the suspect as armed and dangerous, and warned residents to call 911 and not approach him if they see him.
Shortly after he escaped, authorities ramped up security at local churches and other places of worship and shut down the Janesville School District for a day. School is closed for spring break until Tuesday.
In the manifesto, the suspect threatens to steal weapons and use them against public officials or schools. Investigators said they analyzed the manifesto and discovered grievances focusing on several topics but no specific threat to any group.
"There were two themes in the manifesto," Janesville police Chief David Moore said. "He was anti-government, and he certainly had his concerns on the federal government and (was) anti-religion. Those seem to be the two strongest themes."
More than 150 officers from local, state and federal law enforcement agencies are searching for him.
"All local, state and federal agencies continue to be involved in this search and additional resources have come in from Chicago and Minneapolis/St. Paul, Minnesota," the Rock County Sheriff's Office said.
Cell phone video
Knudson said the White House has received the manifesto. CNN has contacted the White House for comment but hasn't received a response.
Authorities released a cell phone video that appears to show Jakubowski at a post office, mailing a bulky envelope addressed to Trump at the White House.
The video, which authorities said was posted on social media, shows Jakubowski's name and a Janesville return address on the manifesto's envelope. Authorities declined to confirm what social media platform the video was on.
A neighbor of the suspect's said he saw no signs of trouble.
"Normal guy, normal guy," Phil Scriven said. "He would just sit out here and work on his truck."
Donald McLean, Jakubowski's stepfather, said the two are estranged and haven't talked for two years. But the suspect has not been a fan of authority, especially police officers, since age 17, he said.
"He just generally started hating society, hating police, hating the government, hating rules, regulations, controls, limits," McLean said.
McLean said he fears things could end badly if police confront Jakubowski. His message to his stepson is to turn himself in.
"Stop whatever you're doing, whatever you're thinking, put everything down and call 911," he said. "We can start working through the rest of this."
Jakubowski has been charged with three felonies: burglary to arm himself with a dangerous weapon, theft and possession of burglarious tools, according to a criminal complaint.
The FBI has doubled its reward to $20,000 for information leading to his arrest.
Janesville is more than 70 miles southwest of Milwaukee, near the Illinois border.