The authorities arrested a Las Vegas man who discussed attacking a local synagogue and charged him on Friday in connection with bomb-making materials found in his home, officials said.

The man, Conor Climo, was charged on Thursday with one count of possession of an unregistered firearm, namely, the component parts of a destructive device, the Department of Justice said in a statement.

Image Conor Climo tried unsuccessfully to recruit a person who was homeless to conduct surveillance on a local synagogue and other targets leading up to an attack, officials said. Credit... KTNV 13 Action News, via Associated Press

Prosecutors said that Mr. Climo, 23, had communicated with people who identify with a white supremacist extremist organization, and had encrypted online conversations in which he regularly used derogatory racial, anti-Semitic and homophobic slurs.