(CNN) A 27-year-old man who allegedly espoused white supremacist ideology online was arrested by the FBI and accused of plotting to bomb a synagogue in Colorado.

Richard Holzer had brought a knife and a mask to a motel room and was examining inert pipe bombs prepared by undercover agents moments before he was arrested late Friday, according to a criminal complaint.

Holzer is charged with attempting to obstruct the free exercise of religious beliefs with the attempted use of explosives -- a hate crime. In court documents, officials called him a domestic terrorist and described his alleged anti-Semitic ideology and desires for a racial holy war.

According to the complaint, Holzer talked about killing Jews in forums online and shared video of himself casing a synagogue in Pueblo. He described himself as a skinhead, and shared pictures of himself with other social media users with guns and knives alongside white supremacist symbols, the complaint says.

Holzer, according to prosecutors, wrote on one Facebook account: "I wish the Holocaust really did happen .... they need to die."

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