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

Nancy Guthrie Sheriff Chris Nanos says he's 'still positive' case will be resolved despite long wait

Sheriff Chris Nanos Says Nancy Guthrie Case Will Be Solved Despite Long Wait

Pima County Sheriff Chris Nanos says he remains “still positive” that investigators…
Seattle Police Chief Faces Questions Over Chicago Home and Absence After Mass Shooting - Internewscast Journal

Seattle Police Chief Faces Questions Over Chicago Home and Absence After Mass Shooting

Seattle Police Chief Shon Barnes is facing renewed questions after he was…
Fauci Faces Senate GOP Questions Again Over Pandemic Origins - Internewscast Journal

Fauci Faces Senate GOP Questions Again Over Pandemic Origins

WASHINGTON — Dr. Anthony Fauci, the prominent U.S. infectious disease scientist who…
Delta Jet’s Collision Alarms Sound in Atlanta Airport Close Call - Internewscast Journal

Delta Jet’s Collision Alarms Sound in Atlanta Airport Close Call

Cockpit warning systems sounded as two Delta Air Lines aircraft came dangerously…
Salman Rushdie Attacker Hadi Matar Convicted on Federal Terrorism Charges in Lecture Stabbing - Internewscast Journal

Salman Rushdie Attacker Hadi Matar Convicted on Federal Terrorism Charges in Lecture Stabbing

A federal jury on Wednesday convicted a man on terrorism-related charges stemming…
Lindsay Clancy’s Ex-Husband Reveals Pill Use Details as Expert Says Evidence Could Sway Murder Trial - Internewscast Journal

Lindsay Clancy’s Ex-Husband Reveals Pill Use Details as Expert Says Evidence Could Sway Murder Trial

If you or someone you know is experiencing suicidal thoughts, call the…
Two families sue North Dakota hospital on allegations babies were switched at birth

French Man Finds 5 Babies’ Bodies Hidden in Boxes at Home

American mother describes being trapped with children in France wildfires American mother…
Will the Fed Raise Rates in July? Experts Share Forecasts - Internewscast Journal

Will the Fed Raise Rates in July? Experts Share Forecasts

The Federal Reserve is widely expected to keep interest rates on hold…
Mega Millions $800M Jackpot Winning Ticket Sold in Florida: Drawing Results - Internewscast Journal

Mega Millions $800M Jackpot Winning Ticket Sold in Florida: Drawing Results

The Sunshine State has a major reason to celebrate this summer. A…
Mega Millions $800M Jackpot Won in Florida: Winning Numbers and Drawing Results - Internewscast Journal

Mega Millions $800M Jackpot Won in Florida: Winning Numbers and Drawing Results

The summer lottery excitement just reached a new high. A Mega Millions…
Painful Mishap Ends Idaho Unicyclist’s Guinness Record Bid - Internewscast Journal

Painful Mishap Ends Idaho Unicyclist’s Guinness Record Bid

An Idaho record-chaser aiming to land a Guinness World Record by juggling…
BTS Opts Out of Submitting Music for 2027 Grammy Awards Consideration - Internewscast Journal

BTS Opts Out of Submitting Music for 2027 Grammy Awards Consideration

BTS, the South Korean K-pop supergroup, said Wednesday that they will not…