17. May 28, 2016 in San Diego, California. Trump supporters pepper-sprayed protesters outside a rally.
12. March 19, 2016, in Tucson, Arizona. A protester at a Trump rally was sucker-punched and kicked by a 32-year-old man who was then arrested on an assault charge.
11. March 19, 2016, in Tucson, Arizona. A Trump security official and Trump campaign manager Corey Lewandowski appeared to grab and pull a protester at the same Tucson rally.*
10. March 9, 2016, in Fayetteville, North Carolina. A black protester being escorted out of a Trump rally was sucker-punched by a white bystander:
9. March 8, 2016, in Jupiter, Florida. Politico reports that Trump campaign manager Corey Lewandowski "forcibly" grabbed a female reporter for the right-wing Breitbart news site, "nearly bringing her down to the ground," when she attempted to ask a question after a Trump press conference.
8. March 1, 2016, in Louisville, Kentucky. A black woman was surrounded and shoved by a number of individuals at a Trump rally.
6. Dec. 14, 2015, in Las Vegas. Individuals at a Trump rally yelled "Sieg Heil" and "light the motherfu*** on fire" toward a black protester who was being physically removed by security staffers.
http://www.slate.com/blogs/the_slatest/2016/03/02/a_list_of_violent_incidents_at_donald_trump_rallies_and_events.html