Brian Thompson

Manhattan prosecutors filed murder and other charges against Luigi Mangione Monday night. Earlier in the day Mangione was arraigned on firearms and forgery charges in Pennsylvania after his arrest.

Manhattan prosecutors Monday night filed murder and other charges against Luigi Mangione, 26, in the killing of UnitedHealthcare's CEO last week, according to online court documents.

The public is racing to find evidence that might lead to the gunman who killed health insurance CEO Brian Thompson. When does crowdsourcing detective work help police, and when can it cause harm?

Authorities in New York City said the gunman took a taxi to the George Washington Bridge Bus Station. The FBI said it was assisting the NYPD in the investigation and offering a reward up to $50,000.