Tony Costa (August 2, 1944 – May 12, 1974) was a serial killer active in Massachusetts during the late 1960's. He was suspected of killing seven women: Bonnie Williams, Diane Federoff, Barbara Spaulding, Sydney Monson, Susan Perry, Patricia Walsh, and Mary Anne Wysocki but convicted of killing only two: Walsh and Wysocki. On February 8, 1969, while looking for the bodies of Patricia Walsh and Mary Anne Wysocki, police discovered Susan Perry. Perry had been missing since the previous Labor Day.