WASHINGTON (AP) — Misleading claims about the neo-Nazi gunman responsible for Saturday’s mass shooting at a Dallas-area shopping center are reverberating across Twitter, in large part because of Twitter owner Elon Musk. Musk has questioned whether the man identified by authorities as the shooter, Mauricio Garcia, really had an account on a Russian social media platform, and Musk suggested that revelations about the shooter’s background could be a “psyop,” or psychological operation, in which the public is misled about the real details of the shooting. Garcia proclaimed his white supremacist views on social media and sported Nazi tattoos. Authorities and...