At least two law enforcement officers were killed in separate incidents on the Martin Luther King Jr. holiday, according to local officials.
In Toledo, Ohio, a standoff between police and a suspected church arsonist ended Monday night with the deaths of the suspect and a police officer, according to an announcement by the Toledo Police Department.
And in Sacramento, California, a car chase ended in a shootout at the California Expo Center, resulting in the deaths of a sheriff's deputy, a K-9 officer and the suspect.
So far in the first 19 days of 2021, at least 17 police officers have died in the line of duty, several of them dying of Covid-19, according to the Officer Down Memorial Page.
Toledo authorities announced late Monday night that 24-year-old police officer Brandon Stalker had been shot and killed in a standoff.
Stalker was fatally shot by Christopher Harris, 27, the suspect in a church arson case, according to NBC affiliate WNWO.
Police had a warrant for Harris' arrest for allegedly scrawling graffiti and setting fire to the doors of the city's historic Rosary Cathedral early Monday morning.
When Harris was confronted at his home on Monday afternoon, he brandished a firearm. Officers set up a perimeter and called in a SWAT team.
Negotiators worked on the situation "for hours," Toledo Police Chief George Kral said Monday at a press conference, but "it was not successful."
Police used gas to drive Harris outside. He emerged with two firearms and started shooting. Stalker, who was working perimeter, was struck once and killed. Officers returned fire and killed Harris.
Stalker, who served on the Toledo police force for just over two years, is survived by a young child and a fiancée, Kral said.
"It's a very sad day for the city of Toledo and specifically the Toledo Police Department," Kral said.
Later that day, in California, another deadly standoff started with a car chase and ended in fatal crossfire at a Sacramento fairground.
In a press conference early Tuesday morning, Sacramento Sheriff Scott Jones told NBC News affiliate KCRA that a car pursuit began after 10 p.m. on Monday night and ended with a crash near the horse track at the California Expo Center.
A standoff ensued when the suspect, who authorities identified as a parolee, would not leave his car. Jones told KCRA that authorities used less-than-lethal rounds to try to force the suspect out of his vehicle.
The suspect remained in his vehicle until a K-9 unit was unleashed. The dog, the suspect and one sheriff's deputy were all killed in the ensuing gunfire.
One other deputy was hospitalized with injuries, Jones told KCRA, which reported that the investigation is expected to be "very complex" because of the crossfire.
"There were a lot of shooting officers, there were a lot of shots fired and so obviously the crime scene investigators will want to do their best to try to account for each of the shots," Jones said at the early morning press conference.
"There's going to be a lot of interviews to try and get some of that information and obviously some of those interviews will take some time."
The Sacramento sheriff's media office did not respond to a NBC news request for comment on the identity of the deceased officer, suspect or dog.