Days after a man in a clown mask allegedly lit a Chicago police vehicle on fire in broad daylight, investigators tracked him down -- in part because he has the word “PRETTY” tattooed across his neck, according to federal prosecutors.

Timothy O’Donnell, 31, was arrested Tuesday on a federal arson charge, according to the Department of Justice (DOJ).

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Days after a man in a clown mask allegedly lit a Chicago police vehicle on fire in broad daylight, investigators tracked him down in part because he has the word “PRETTY” tattooed across his neck. (Courtesy: DOJ)

“Anyone involved in destructive behavior -- such as setting fire to a police car -- should know that federal law enforcement will use all tools available to us to hold them accountable,” U.S. Attorney John Lausch said.

Photos of the scene show a man in a mask, similar to ones used in the 2019 “Joker” movie, a "Batman" spinoff that depicts citywide rioting leading up to its final scene.

Photos of the scene show a man in a mask, similar to ones used in the 2019 “Joker” movie, a "Batman" spinoff that depicts citywide rioting leading up to its final scene. (Courtesy: DOJ)

In the images, the masked man can be seen handling a police vehicle’s gas tank and later sitting and posing near the flaming SUV. In one of the photos, the “PRETTY” tattoo is visible.

The FBI special agent handling the investigation said he also reviewed video that showed the entire May 30 incident.

In the images, the masked man can be seen handling a police vehicle’s gas tank and later sitting and posing near the flaming SUV. (Courtesy: DOJ)

Police had been in the area responding to reports of “various malfeasances and unrest” as protests grew in cities around the country following the death of George Floyd in police custody in Minneapolis on May 25.

The Chicago Police Department vehicle was parked on the 200 block of North State Street when it burst into flames.

Authorities executed a search warrant at O’Donnell’s home Tuesday and found an identical “Joker” mask in the bedroom, according to a criminal complaint. After his arrest, he allegedly waived his right to remain silent and admitted he was the one wearing the mask in the photos.

Timothy O’Donnell, 31, was arrested Tuesday on a federal arson charge, according to the Department of Justice (DOJ).

If convicted, he faces five to 20 years in prison.

Protests have been held around the country -- some peaceful and some resulting in looting, rioting and other violence.

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In a separate case, federal prosecutors arrested an Illinois man whom they accused of passing out explosives at a protest in Minneapolis. They tracked him down, in part, because he had “distinctive gold teeth.”