Joe Mahr

Joe Mahr is an investigative reporter who has written about topics ranging from government corruption and court mismanagement to lax policing efforts and questionable lottery tactics. An Ohio University graduate, Mahr joined the Tribune in 2009. He was on a team that won a Pulitzer Prize in 2004 and on another that was a finalist in 2015.

People in handcuffs are escorted by federal agents to white vans parked outside the Intensive Supervision Appearance Program office run by Immigration and Customs Enforcement in the South Loop on June 4, 2025. (Eileen T. Meslar/Chicago Tribune)

ICE arrests increase across Chicago under Trump, many with no convictions, data shows

July 23, 2025 at 11:39 a.m.

A Tribune analysis reveals a sharp overall increase in the number of people booked into detention processing centers in the Chicago area in the 150 days since President Trump was...

Marles Blackman enters the Markham courthouse with an attorney on June 27 after a dinner break for the jury deliberating in her murder trial. (John J. Kim/Chicago Tribune)

Stalled Justice: Mother convicted of killing her toddler, 13 years after charges filed

July 1, 2025 at 11:36 a.m.

In the notoriously slow Cook County court system, a jury has convicted a south suburban woman of murder in the 2011 death of her son.

The basketball courts in Douglass Park in Chicago are empt, June 27, 2025, a day after two teens were shot nearby, one fatally, allegedly. (Terrence Antonio James/Chicago Tribune)

North Side man charged with killing teen, wounding another at West Side park

June 29, 2025 at 11:06 a.m.

A 55-year-old Lakeview man has been charged with murder after police said he shot two teen boys Thursday evening in Douglass Park – killing a 15-year-old and seriously wounding a...

Chicago Budget Director Annette Guzmán, left, and Chicago Mayor Brandon Johnson speak about the city’s budget before the start of a community event at the Harold Washington Library Center in Chicago on Feb. 4, 2025. (Terrence Antonio James/Chicago Tribune)

Soaring Chicago police lawsuit payouts hit record amount — and more are on the way

May 26, 2025 at 12:57 p.m.

Through May alone, the City Council has already approved $145.5 million in taxpayer payments to settle lawsuits alleging police misconduct, a record number.

April 16: A police dog sniffs newly arriving detainees in an underground tunnel at Cook County. (Antonio Perez/Chicago Tribune)

With Cook County Jail’s population again on the rise, officials weigh the reasons

April 20, 2025 at 6:55 p.m.

After a decline following statewide bail reform — and years of reductions prior to that — the county’s jail population has begun to tick up once again.

John Fulton, right, walks away after hugging Anthony Mitchell at a press conference outside the Dirksen U.S. Courthouse on March 10, 2025, after a federal jury awarded over $120 million in damages to the men in their civil trial for wrongful conviction. (Eileen T. Meslar/Chicago Tribune)

Federal jury awards $120 million in wrongful-conviction case

March 10, 2025 at 9:32 p.m.

A federal jury in Chicago on Monday awarded $120 million in damages to two wrongfully convicted men who spent more than 15 years in prison.

A sheriff's deputy walks outside the Clay County Justice Center, home to a U.S. Immigration and Customs Enforcement detention center, on Jan. 28, 2025, in Brazil, Indiana. (Armando L. Sanchez/Chicago Tribune)

The hidden world of Chicago ICE arrests: One month after Trump’s inauguration, a partial look at those detained

February 24, 2025 at 9:53 a.m.

As ICE refuses to provide basic information about the recent arrests in Chicago, jail logs offer a rare glimpse into the opaque immigration system.

Jason Peña with his father, Vicente Peña Jr., in an undated photo. Both were shot, along with two other men, while traveling in Mexico on Friday, Dec. 27, 2024. Vicente Peña was killed, along with the other two men, while Jason Peña was critically injured. (Ana Cabral)

Injured Chicago-area teen being flown to US after Mexico shooting that killed his father and uncle

January 1, 2025 at 5:25 p.m.

Jason Peña, 14, of the Pilsen neighborhood in Chicago is being flown to a Texas hospital following a Friday shooting in Mexico that killed his father and uncle.

The Illinois Reform Commission, chaired by former federal prosecutor Patrick Collins, second from left, unsuccessfully proposed in 2009 that state and local law enforcement should be allowed to use wiretaps to pursue corruption investigations. David Hoffman, then Chicago’s inspector general, is at left. (Abel Uribe/Chicago Tribune)

Corruption has burdened Illinois since its earliest days. But change is possible. Here’s how.

December 22, 2024 at 8:49 a.m.

Illinois' culture of corruption may leave many feeling hopeless. But elected officials, from Gov. JB Pritzker to township trustees, have the power to make a difference.

People wait in a long line to vote at the Board of Elections Loop Supersite late on Election Day, Nov. 5, 2024. (Eileen T. Meslar/Chicago Tribune)

Turnout high in Chicago area for presidential election; long waits at some sites

November 6, 2024 at 12:17 a.m.

Voters turned out in the high numbers typical of a presidential election Tuesday, with waits at some polling places but few significant problems reported.

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