Sources for more ideas
http://www.pbs.org/teachers/thismonth/justice/index3.html - a collection of activities from TPT, MN piblic television
http://www.tolerance.org/teach/activities/activity.jsp?ar=903 - Teaching Tolerance lesson plan
http://www.teachersforjustice.org/database.html - group of lesson plans by Chicago teachers (still in progress)
One somewhat controversial engagement tactic (but useful if used properly) is the "blue eyes-brown ...
This provides several examples of appropriate teaching strategies for teaching justice to high school students. Note: provides examples only, not an essay.