At least one sniper, identified as Micah Johnson, fatally shot five officers and injured seven others during a peaceful Black Lives Matter protest in Dallas on July 8. It has been declared the deadliest attack on law enforcement since the 9/11 terrorist attacks, according to The Washington Post. While this is an isolated incident, which President Obama called a "vicious, calculated, and despicable attack on law enforcement," there is an alarming connection between the shooting of police officers and the ongoing political fight over gun control. A study released by Harvard University found that police officers are more likely to be killed in states that have more guns, like Texas. The study looked at FBI data about police-officer deaths from 1996 to 2010 alongside a gun ownership survey from the Centers for Disease Control and Prevention. Researchers found that among the eight states with the least gun ownership, there's a 13.5% average rate of police fatalities over those 14 years. However, there's a 52% average rate of police fatalities in the 23 states with the highest gun ownership. Here's what that means, according to The Washington Post: "Line-of-duty homicide rates among police officers were more than three times higher in states with high gun ownership compared with the low gun-ownership states. Between 1996 and 2010, in other words, there were 0.31 officer fatalities for every 10,000 employed officers in low gun-ownership states. But there were 0.95 fatalities per 10,000 officers in the high gun-ownership states." That's a clear, statistical correlation between civilian gun ownership and police-officer fatalities. The study found that police officers "working in states with higher levels of gun ownership faced a greater likelihood of being shot and killed on the job compared with their peers in states with lower gun ownership."