Gazette: McCarthy said he thinks there is an assumption by some that the only money in the accounts was earned by students working in jobs.

Title quote is from this Gazette article: 
http://www.gazette.net/article/20150513/NEWS/150519765&template=gazette

Then why were bank accounts set up using the students' social security number and why were W-2's issued?
 
It seems that State's Attorney John McCarthy isn't following his own investigation. The Washington Post has already reported that these were work-study funds and W-2's were issued.

http://www.washingtonpost.com/local/education/prosecutors-find-no-criminal-activity-at-school-for-special-education-students/2015/05/06/20e5a2ee-f348-11e4-b2f3-af5479e6bbdd_story.html