Four policemen have been shot in 24 hours across the US in the latest in a series of attacks on law enforcement.
One officer was shot dead in San Antonio, Texas, and another was shot in the face in St Louis, Missouri, though he is expected to survive.
At least two of Sunday's attacks were ambushes. Two other officers were shot elsewhere in Missouri and Florida.
In the first incident, 50-year-old Benjamin Marconi, a 20-year veteran of the San Antonio force was fatally shot as he sat in his squad car during a routine traffic stop outside the city's police headquarters.
The assailant stopped his car behind the police cruiser, walked up and shot the officer in the head through the window as he was writing a ticket, San Antonio Police Chief William McManus told a news conference on Monday.
The gunman then reached through the window, fired a second shot into the officer, returned to his vehicle and sped away.
Also on Sunday, a 46-year-old St. Louis police sergeant was shot in the face by a person in a car who pulled up beside the officer's cruiser at an intersection then fled. St. Louis Police Chief Sam Dotson said the wounded officer was conscious and able to speak after the attack.
The suspect was later killed in a shootout after officers spotted his car, police said on Monday.
Meanwhile, a third police officer was shot on Sunday during a traffic stop on Sanibel Island on Florida's Gulf Coast but was not seriously hurt, local media reported.
The officer was treated for a shoulder wound, according to the reports, while the suspect was apprehended at his home on an island off Ft. Myers.
In a fourth incident, a police officer in Kansas City, Missouri, was shot and wounded during a struggle with an armed suspect who tried to flee after a traffic stop, police said.
The suspect was killed and a Kansas City police spokeswoman said investigators were determining whether the officer was shot accidentally by one his colleagues.
The attacks revived memories of deadly ambushes against police in Texas and Louisiana in July.
Fifty-seven US law enforcement officers have been fatally shot this year, a 68 percent increase from the same period in 2015.
The attacks do not appear to be connected, police said.
The latest shootings come amid an intense national debate over the role of law enforcement and especially the use of force by officers against minorities.
- Reuters / RNZ