PITTSBURGH (KDKA) — Pittsburgh police and ATF agents searched the home of a man accused of leaving explosives next to a downtown Pittsburgh building.

Matthew Michanowicz, 52, is charged with possessing weapons of mass destruction and possession of explosive or incendiary materials or devices.

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(Photo Credit: Allegheny County Jail)

On Thursday, police were seen going in and out of a home on Republic Street in Duquesne Heights.

According to police, Michanowicz was seen riding up to PNC Plaza on a bike with a backpack on Sunday.

Surveillance footage allegedly shows him getting off the bike, looking around and walking over to bushes, where he planted the backpack.

Police got reports of a suspicious package in the area on Monday and found the backpack. They say multiple explosives were inside.

When police confronted Michanowicz, he admitted to being downtown to look at the damage from Saturday’s riots, according to police documents. He denied planting the backpack even after police showed him photos and videos of the incident.

Court records show he posted bond on Thursday.

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He is scheduled for a preliminary hearing in August.