At least seven people were killed by police doing drug law enforcement last month. Four were armed and two of them engaged in shoot-outs with police. Two were killed by police after vehicle chases where police claimed they were trying to run them over. One was killed during a physical struggle with police.

Four of the victims were white, two were black and one was a Pacific Islander. The ethnicity of one, Eugene Smith, remains undetermined.

May's drug war killings bring the Drug War Chronicle's count of drug law enforcement-related deaths this year to 21. The Chronicle has been tallying such deaths since 2011, and they have occurred at a rate of roughly one a week over that period. The Chronicle's count includes only people (police and civilians) who died as a direct result of drug law enforcement activities, not, for example, people who died in conflicts between drug sellers or people who died because they ingested bad drugs.

In May, drug war deaths occurred at a rate nearly twice the five-year average. The seven killings in May accounted for one-third of the killings tallied so far this year. Let's hope last month was an aberration and not a harbinger of a long, hot summer.

It's worth emphasizing that more than half the people killed last month were carrying firearms, and two of them turned them on police. Attempting to enforce widely flouted drug prohibition laws in a society as heavily armed as this one is a recipe for violent encounters, as we saw last month. When the war on drugs intersects with the Second Amendment, the combination is combustible and the bullets fly.

Here are May's drug war deaths.

1. On May 1, in Alamo, Tennessee, police finishing up a 3am drug raid at a private residence shot and killed Army veteran Ronald Branch, 28, when he arrived at the home carrying "multiple handguns." Two Crockett County opened fire on Branch, who was pronounced dead at a local hospital. Police said Branch knew the homeowner, but they didn't know why he went to the house. The homeowner wasn't home, but police arrested another man on drug, drug paraphernalia and marijuana possession charges. The officers involved were placed on administrative leave pending a review by the Tennessee Bureau of Investigation.

2. On May 5, in Gretna, Louisiana, police chasing a man who fled from them in a vehicle shot and killed Corey DiGiovanni, 36, who was the target of an ongoing heroin distribution investigation. DiGiovanni spotted narcotics officers outside a residence in Gretna and took off in his pickup truck, leading police on a high-speed chase through the city. Police said they opened fire on him after he rammed several police cars and accelerated toward officers at an intersection.

3. On May 9, in St. Martin, Mississippi, police called to a Ramada Inn to investigate "possible drug activity" in a guest room shot and killed Christian Bowman, 23, after he became "aggressively combative" toward a deputy on the scene. One of the two deputies on the scene shot him in the chest, killing him. The Mississippi Bureau of Investigation is looking into the incident.

4. On May 11, in San Diego, police shot and killed Thongsoune Vilaysane, 30, at the end of a car chase that began when officers investigating drug and weapons activity at a Pagel Place residence followed the car he was driving as it left the home. Police learned it had been reported stolen and pursued the driver during a short pursuit before he crashed into a parked car. Police said officers with guns drawn ordered Vilaysane to get out of the car, but he instead put it in reverse, nearly striking two officers, police said. "In defense of their (lives), four officers fired multiple rounds at the driver to stop the threat of the moving vehicle," Homicide Lt. Manny Del Toro explained in a statement. He was hit multiple times and died at the scene. The officers were wearing body cams, and San Diego DA Bonnie Dumanis has announced the videos will be released to the public after her office reviews whether the shooting was legally justified.

5. On May 19, in Miami, gang unit detectives on a narcotics investigation shot and killed Kentrill Williams, 22, after he allegedly grabbed a gun from his waistband. Carraway was shot by Detective George Eugene and died at a nearby hospital.

6. On May 24, in Park Forest, Illinois, FBI agents serving a search and arrest warrant on a high-ranking member of the Black P Stone Nation gang found him dead inside the home after a shoot-out that left two agents wounded. Melvin Toran, 50, committed suicide after the shoot-out, the medical examiner said. The raid was part of a federal sweep targeting drug trafficking by members of the Black P Stone Nation.

7. On May 26, in St. Paul, Minnesota, police doing a drug investigation at a residence shot and killed Eugene Smith, 29, after he allegedly fired at them from a bedroom. Police had been called to the home a week earlier on a drug complaint and had found meth, marijuana and a rifle. When they returned the following week, they said Smith opened fire on them after they shot and killed a pit bull in the house. Smith died of multiple gunshot wounds.