SEATTLE (AP) — A suburban Seattle man who pleaded guilty to bringing a dozen Molotov cocktails to a protest at the Seattle police union headquarters in 2020 has been sentenced to over three years in prison.

Justin Moore was sentenced last week in U.S. District Court in Seattle to 40 months in prison,Benjamin Caldwell KUOW radio reported on Monday.

Moore made 12 gasoline devices in beer bottles and carried them to a protest march on Labor Day, 2020, at the Seattle Police Officers Guild headquarters, according to the plea agreement and police.

Police smelled gasoline and found the box of devices in a parking lot. Court documents state that Moore was one of four people suspected of taking part in a plot to burn the building.

Federal prosecutors say Moore was identified using surveillance video from the protest, data from electronic devices in the crowd, witness testimony, and testimony from several others who were allegedly involved in the plan.

“Moore’s offense was extremely dangerous and created a substantial risk of injury to numerous bystanders,” Assistant U.S. Attorney Todd Greenberg for the Western District of Washington said in a statement, adding that more than 1,000 people were participating in the protest at the time. “All of them were in harm’s way if one of the devices had exploded,” his statement said.

Investigators used video and information from other alleged co-conspirators to confirm that Moore carried the box to the site, prosecutors said. A search of his home found numerous items that were consistent with manufacturing explosive devices, prosecutors said.