The sheriff's office said that "hundred and fifty local, state and federal law enforcement officers" had been deployed in the search and that federal authorities were looking into leads related to Jakubowski outside of the state.
Jakubowski allegedly broke into the Armageddon Supplies gun shop in Janesville Tuesday at 8:40 p.m. and stole about 16 high-end firearms.
Officials say they have also found a 161 page anti-government manifesto that Jakubowski sent to President Trump.
"Mr. Jakubowski is known well to the officers of the Janesville Police Department and the Rock County Sheriff's Department", Janesville Police Chief David Moore said in a press conference on Friday.
A nationwide manhunt is on for a Wisconsin man wanted for a series of crimes including stealing over a dozen guns and allegedly plotting mass violence targeting law enforcement and political figures.
According to authorities, Jakubowski also has acquired a bulletproof vest and helmet.
The FBI is offering a $10,000 reward for any information that leads to his arrest.
US strike on Syrian air base has limited impact on Assad
But Syria and its Russian backers have many air bases and lots of military infrastructure in the country. Damascus has strongly denied carrying out the attack and says it does not use chemical weapons.
Among the places authorities are patrolling are churches, due to Jakubowski's anti-religious views.
Joseph Jakubowski is accused of burglarizing a Wisconsin gun shop on April 4 before disappearing.
The registered owner of the vehicle involved in the fire is Jakubowski whose last listed residence is in Janesville.
The hunt continues Monday for a man suspected of stealing firearms from a Wisconsin gun store who sent an anti-government manifesto to President Donald Trump and has threatened to carry out an unspecified attack, sheriff's officials said. However, the sheriff's office has said an associate of Jakubowski who received a copy of the manifesto has been cooperating. Bethlehem Lutheran Church canceled all Sunday services as a precaution and Sun Prairie police said at the time it would provide extra patrols around houses of worship during the weekend.
UPDATE (WKOW) - Rock County Commander Troy Knudson tells 27 News two tactical teams raided the home of Joseph Jakubowski Saturday night after getting a tip that he had returned home.
Wisconsin officials in Janesville told Fox News 6 in Milwaukee Friday that Jakubowski is now considered armed and unsafe, and that he's not a stranger to the police.
The video was obtained from a social media network by law enforcement officials, who have declined to say where it was posted or who shot it.