Shaw began his broadcasting career as an anchor and reporter for WNUS in Chicago. He then worked as a reporter for the Westinghouse Broadcasting Company in Chicago, moving later to Washington as the White House correspondent. He worked as a correspondent in the Washington Bureau of CBS News from 1971 to 1977. In 1977, he moved to ABC News as Latin American correspondent and bureau chief before becoming the Capitol Hill Senior Correspondent. He left ABC in 1980 to move to CNN as co-anchor of its PrimeNews broadcast, anchoring from Washington, D.C.. Shaw's coverage of the 1981 assassination attempt on U.S. president Ronald Reagan (with Shaw joined by former CBS News correspondent Daniel Schorr, one of the first on-air personalities hired by the fledgling cable channel) is credited as helping to establish CNN as a credible and reliable broadcast news source at an early point in the network's history.