<Li> Partnerships that are created between field offices and local law enforcement during the course of investigations being used to gather both protective intelligence and in coordinating protection events . </Li> <P> The agency's primary investigative mission is to protect the payment and financial systems of the United States from such crimes as financial institution fraud, computer and telecommunications fraud, false identification documents, access device fraud, advance fee fraud, electronic funds transfers and money laundering as it relates to the agency's core violations . </P> <P> After the 1901 assassination of President William McKinley, Congress also directed the Secret Service to protect the President of the United States . Protection remains the other key mission of the United States Secret Service . </P> <P> The Secret Service is authorized by law to protect: </P>

When did secret service begin protecting the president