Chicago man Mario Santoyo charged with possession of knife in hours-long standoff at Dirksen Federal Building downtown: officials

CHICAGO (WLS) — The ABC7 I-Team has learned that a man is facing a felony charge for allegedly using a knife during a standoff at a federal building in Chicago.

A standoff at the Dirksen Federal Building downtown ended after roughly nine hours Tuesday night, officials said.

Just before 8 p.m., federal agents were seen rushing toward the man who had been standing in the building’s lobby since about 11 a.m., with a knife.

ABC7 Chicago is now streaming 24/7. Click here to watch

The man was on the ground surrounded before being put on a stretcher.

The individual has been identified as Mario Santoyo, age 38, of Chicago. According to the U.S. Attorney’s Office, he is charged with the felony of “possession of a dangerous weapon in a federal facility with intent to use the weapon in the commission of a crime.”

READ MORE | Process of protection behind safe outcome of hours-long standoff at Dirksen Federal Building

According to a news release, Santoyo reportedly entered the building seeking to “speak with the FBI about ‘gangsters’ or ‘gangbangers’ who were allegedly trying to kill him.”

“The defendant created a dangerous situation for himself, law enforcement, and the thousands of federal employees and members of the public inside the Dirksen Building,” U.S. Marshal LaDon A. Reynolds said in a statement. “The standoff in this case was peacefully resolved thanks to the courage and professionalism of the law enforcement officers from the U.S. Marshals Service and FBI. I am deeply appreciative of this U.S. Attorney’s strong partnership with the U.S. Marshals Service and for his strong leadership in choosing to bring a felony charge to hold the defendant accountable for his intolerable actions.”

Santoyo was hospitalized after the standoff, and he appeared in federal court Friday afternoon.

A judge ordered him to be held in federal custody.

Santoyo will be back in court next Thursday for his detention hearing.

Copyright © 2025 WLS-TV. All Rights Reserved.

You May Also Like
Four accused in alleged anti-Israel University of Michigan threat case released on bond

Four charged in alleged anti-Israel threat case at University of Michigan released on bond

Several college-age activists accused of plotting to threaten University of Michigan officials…
Knicks fans ignite school bus on fire

Knicks Fans Set School Bus Ablaze During Postgame Unrest

Celebrations over Knicks mania spiraled into chaos in Times Square, where fans…
Florida woman mauled to death by dogs that had allegedly terrorized neighborhood, owner charged in killing

Hero Neighbor’s Partner Killed by Dogs in Tragic Twist After He Saved Victim in Similar Attack, Court Records Reveal

Florida woman mauled in dog attack New details are surfacing about earlier…
Mexican authorities discover body in trunk near Iranian soccer team's World Cup training grounds: report

Report: Body Found Near Iranian Team’s World Cup Training Base in Mexico

Mexican authorities have found a decomposing body bearing “signs of violence” near…
Multiple people wounded in shooting at South Carolina's largest mall, authorities detain suspects: report

South Carolina Mall Shooting Leaves Several Injured; Suspects Detained, Report Says

Several people were injured Saturday afternoon when gunfire erupted at South Carolina’s…
Howard professor blames Austin Metcalf's father for his murder in sick Substack rant

Howard professor sparks outrage after blaming Austin Metcalf’s father for killing in Substack post

A Howard University journalism professor drew backlash after publishing a Substack post…
New batch of UFO files released by the Pentagon under Donald Trump administration describe spinning discs and more

Pentagon Releases New UFO Files from Trump Administration Detailing Spinning Discs and Other Sightings

WASHINGTON — One reported object was described as a rotating disc that…
Helicopter footage captures Florida man allegedly abandoning child during high-speed chase from deputies

Florida Man Allegedly Abandons Child During High-Speed Chase, Dramatic Helicopter Video Shows

A Florida man was arrested this week after dramatic video captured him…
YouTuber Reckless Ben Flees to Mexico over Star Wars Lego dispute

YouTuber Reckless Ben Escapes to Mexico Amid Legal Battle Over Star Wars LEGO Dispute

A California YouTuber caught up in an increasingly strange fight over a…
Fox News Campus Radicals Newsletter: Anti-Kirk teacher honored, ICE supporter expelled, Pride display problem

Campus tensions rise: teacher honored after anti-Kirk remarks, ICE supporter expelled, Pride display sparks controversy

A photograph from Utah Valley University shows Charlie Kirk tossing a “Make…
Raisin heir Bruce Lion was busted for terror threats

Bruce Lion, Heir to Raisin Fortune, Arrested on Terror Threat Charges

Bruce Lion, an heir to the Lion Raisins fortune, has been arrested…
California couple fights off 70-pound black bear with hatchet and water bottle outside their home

California Couple Fends Off 70-Pound Black Bear With Hatchet and Water Bottle Outside Home

A California couple was seriously injured this week after a black bear…