Maryland man charged with threatening to kill Sens. Bernie Sanders, Kamala Harris

A Maryland man is accused of threatening to kill Sen. Bernie Sanders and Sen. Kamala Harris while also threatening to harm attendees at the "March for Our Lives" gun control rally held earlier this year.

Authorities said Nicholas Bukoski is facing three counts of transmitting threats in interstate commerce and two counts of threatening to assault and murder a United States official.

Meanwhile, the 19-year-old was already in jail on charges in Maryland for armed robbery and arson.

The federal case against Bukoski was unsealed after he made his first court appearance in U.S. District Court on June 8 where he pleaded not guilty. He returned to court on Wednesday for another hearing, but still remains behind bars.

Federal court documents said the Crofton man sent three threatening messages back in March.

The first was an Instagram message to Sanders' office. It stated, "Senator, I would watch your back as you're out today … You wouldn't want to be caught off guard when I use my second amendment protected firearm to rid the world of you, you stupid, crazy old fool…"

Two minutes later, a similar Instagram message was sent to Harris' office.

Investigators said a third threat was made to the D.C. Police Department's text tip line regarding the March for Our Lives rally that was led by survivors of the Marjory Stoneman Douglas High School shooting in Parkland, Florida.

Police said Bukoski wrote in part, "I am intending to send the message that gun control, bomb control, or any other kind of weapons control will not stop attacks, it is an issue of the heart. My heart is messed up and evil, and part of me wants to see people suffer."

Bukoski was arrested the following month after Anne Arundel County police said he robbed a 7-Eleven store in Gambrills with a knife back in January. He is also accused of setting a series of fires spanning over a one-year period throughout the Gambrills and Crofton areas.

Surveillance video helped police link him to these crimes.

Bukoski could serve decades behind bars for the state charges and is now facing several more years in federal prison with his latest charges.

FOX 5 reached out to Bukoski's family, but they had no comment.