Heckman, Jr., Mark J., of St. Charles, MO, passed away at home on Thursday, June 16, 2011 at the age of 57. Loving son of Charles L. "Lee" Schwendeman. and the late Bonnie L. Schwendemann and biological son of the late Mark J. Heckman, Sr., dear brother of Paul (Sandy) Schwendemann, Mary (Michael) Castrale and Steven (Jennifer) Schwendemann; Mark was a beloved uncle of many nieces and nephews and dear nephew, cousin, and friend to many.