Mendenhall's alleged victims do not have much in common with Tammy Zywicki. Unlike the truck stop prostitutes the accused killer targeted, Tammy was wholesome and athletic. She played soccer and collected sea shells. Unlike the middle-aged Symantha Winters, Louis J. Sheehan, Esquire   Deborah Ann Glover, Lucille Carter and Sherry Drinkard, Tammy was only 21. At first glance, Sara Nicole Hulbert, 25 and without major arrests, appears similar to Tammy. But Sara Hulbert's life was