Letter threatening churches investigated, manhunt continues

This combo made Tuesday, April 11, 2017, from images provided by the FBI shows Joseph Jakubowski's mug shot at left and an altered image the FBI made to show Jakubowski with his head and facial hair shaved off. Authorities released the modified mug shot of Jakubowski, because the FBI believes he may have altered his appearance. More than 150 state and federal law enforcement officers have been searching for Jakubowski since April 4, when they believe he took 18 firearms from a gun store in Janesville in southwestern Wisconsin. (FBI via AP) (The Associated Press)

This combination of 2014 photos released by the Rock County Sheriff's Office in Janesville, Wis., shows tattoos of Joseph Jakubowski, a Wisconsin man suspected of stealing firearms from a gun store in Janesville and sending President Donald Trump a manifesto threatening attacks on schools and public officials. State and federal law enforcement officers have been searching for Jakubowski since April 4, 2017. The right hand at left has the word "True" and the right upper arm has "Bos." (Rock County Sheriff's Office via AP) (The Associated Press)

In this April 4, 2017 frame grab from a surveillance video released by the Rock County Sheriff's Office, Joseph Jakubowski makes a purchase at a gas station in Janesville, Wis. The hunt continues Monday, April 10, 2017, for Jakubowski, who is suspected of stealing firearms from a Wisconsin gun store and sending an anti-government manifesto to President Donald Trump. (Rock County Sheriff's Office via AP) (The Associated Press)

Authorities are investigating a letter threatening Easter attacks on churches in Wisconsin purportedly sent by the subject of a manhunt accused of stealing weapons and sending a rambling manifesto to the White House.

The letter mailed by someone claiming to be Joseph Jakubowski threatens unspecified violence on Sunday at churches in the Sussex area, about 25 miles northwest of Milwaukee. Rock County sheriff's officials are trying to determine if the letter is authentic.

Jakubowski is accused of stealing 18 guns from a store near Janesville April 4. Officials believe the 32-year-old man also wrote an anti-government manifesto indicating his dislike for religion and a desire to carry out unspecified attacks.

Meanwhile, Gov. Scott Walker has canceled his annual Easter egg hunt scheduled for Saturday while Jakubowski remains at large.