The Nicolet School District says it is no longer investigating a former math teacher, but it is leaving the case open so more victims can come forward.  Ten former students have said they were sexually assaulted by David Johnson over the last three months.  School officials say their decision sends a signal to other victims that they will supportive and willing to help anyone else who was assaulted.  Aurora Health and its healing centers are providing support to all victims at no cost, according to the school district.