Three police officers in three different states were shot in apparently unprovoked attacks in a 12-hour period Sunday, attacks described as “targeted” and “ambush”-style by officials.

A fourth was shot in a suburb of Kansas City, but the circumstances were unclear early Monday morning.

The first and only fatal shooting took place just before noon in San Antonio, directly outside the police station, as a 20-year veteran of the police department issued a traffic ticket from inside his patrol car. The assailant, seemingly unconnected to the original motorist, shot the officer twice — at least once in the head — before fleeing in a black car. No suspect is in custody.

The second shooting was reported at about 7:30 Sunday evening in the city of St. Louis. A 46-year-old officer was sitting in traffic inside his patrol car when another pulled up alongside him. Someone inside shot the officer twice in the face then fled the scene. The 19-year-old suspect was later shot and killed by police when authorities say he fired at officers searching for him. The officer who was shot in the face is expected to survive.

At 8 p.m., the third ambush-style shooting shocked the small coastal Florida town of Sanibel, where for the first time in the city’s history an officer was shot in the line of duty. Like the attack in San Antonio, the Florida officer was sitting in his car after a “routine traffic stop” when, according to the News-Press, a “drive-by shooter” opened fire. The injured officer was treated and released from a hospital, officials said, and the suspect was arrested after a shootout with police.

A fourth officer with the Gladstone Police Department was shot later Sunday night near Kansas City, Mo., reported the Kansas City Star, but it was unclear from initial reports if the shooting was similar in nature to the unprovoked attacks earlier in the day. The officer was expected to survive.

Sunday’s shootings are the most recent in a string of similar attacks that have made headlines this year, beginning with the most extreme of them all, the ambush-style killings of five Dallas police officers in July. Since then, at least a dozen officers have been shot in what officials have called unprovoked attacks.

At least five other officers have been targeted and shot just this month; two fatally in Iowa; one fatally and another non-fatally in Pennsylvania; and one fatally in California.

At a news conference in San Antonio Sunday afternoon, San Antonio Mayor Ivy Taylor said the shooting there was “shocking and sobering,” and asked the community to remain “calm and prayerful” as authorities continued their search for the gunman.

Police Chief William McManus described the suspect as a dark-complected, slim male in his twenties or thirties. Witnesses described the man as dressed in gray pants and a gray shirt, and surveillance photos show him leaving the scene in a black sedan with chrome rims and tinted windows.

“We consider this person extremely dangerous and a clear threat to law enforcement officers and the public,” McManus said.

Later, police published a photo seeking help in identifying a man “in connection” with the shooting, describing him as a “black male, 20-30 years old, 5’7-6′, tall, slim build with a goatee.” It was not clear if the two descriptions were of the same person.

Until the suspect is caught, the police chief said that all officers have been ordered to only conduct traffic stops if they have “cover” from another officer.

While most people spend this week celebrating Thanksgiving with family, McManus said his department “will be burying one of its own because of an ultimate act of cowardice by a suspect who will be caught and brought to justice.”

The slain officer was identified by the chief as Detective Benjamin Marconi, a 50-year-old father and grandfather. He had been with the force for 20 years and was a sex crimes detective who “excelled at his work” at the time of his death, a former colleague told NBC News.

“He was a great father, he was a great officer,” retired detective Roy Naylor told NBC News.

Marconi conducted a traffic stop in front of police headquarters at about 11:45 a.m. Sunday, the chief said. While he was sitting inside the patrol car, another vehicle — the black sedan with chrome rims — pulled up behind the officer. The suspect got out of the car, walked up to Marconi’s driver side window and fired one shot. It struck Marconi in the head.

The suspect then “reached in through the open window and fired a second shot,” the chief said, hitting Marconi in the head again.

The gunman walked back to the vehicle and drove away.

Marconi was taken to a hospital and pronounced dead.

San Antonio police released photos of the suspect’s vehicle and surveillance footage of people who may have witnessed the shooting. Authorities continued their search early Monday morning.

Texas Gov. Greg Abbott called the slaying a “horrific act of violence,” and added that “attacks against law enforcement officers will not be tolerated in Texas.”

Police chief McManus compared the shooting to the targeted attacks on police officers this year, reported NBC News.

“It’s happened here,” he said. “It’s everyone’s worst nightmare.”

More from Morning Mix

Police, citing ‘ongoing riot,’ use water cannons on Dakota Access protesters in freezing weather

The aftermath of the ‘Hamilton’-Trump feud turns ugly in Chicago, gets weird in Canada

Texas teacher who had sex almost daily with 13-year-old student could face decades in prison