A growing backlog at the U.S. Department of Education has some sexual assault victims waiting years to have their cases resolved. Advocates have been encouraging students to file complaints with the department if they believe their schools haven’t handled them properly. Federal officials also are taking a broader look at the schools than they used to when a complaint comes in. More than 100 colleges and universities are now under investigation. Those probes can last more than four years. Advocates say that can leave individual victims hanging so long that they’ve graduated or left campus for other reasons by the time the cases get resolved.