433 U.S. 1 97 S.Ct. 2476 53 L.Ed.2d 538 UNITED STATES, Petitioner,v.Joseph A. CHADWICK et al., Respondents. No. 75-1721. Argued April 26, 1977. Decided June 21, 1977. Syllabus When respondents arrived by train in Boston from San Diego, they were arrested at their waiting automobile by federal narcotics agents, who had been alerted that respondents […]