 Two police officers and a fire paramedic were killed in Burnsville back in February, and Minneapolis officer Jamal Mitchell died in the line of duty in May. National data shows 72 law enforcement officers have died in the U.S. so far this year. Ticks were out in full force earlier this spring and summer, but disease-carrying mosquitoes are more of a problem now. That, according to Minnesota State Department of Health epidemiologist Elizabeth Schiffman, who says ticks start to lay low as temperatures get hot.