Homicides rose nearly 12 percent nationwide last year, according to newly released FBI data, close to the largest percentage increase in half a century. In cities with a population above a quarter million, homicides rose 14.5 percent; cities with a population between half a million and a million saw a 20 percent increase in homicides. The Ferguson Effect — officers backing off of proactive policing under the false charge that they are racist and the resulting increase in violent crime — is real and dangerous. The candidates tonight have the opportunity to show that they intend to change the false narrative about lethally racist policing in this country. If that narrative does not change, more black lives will be lost and more cities will be torn apart with racial violence.