A Massachusetts road-rage altercation left one woman dead and one man behind bars last week, authorities said.

Ryan Sweatt got into "an apparent road rage incident" with another car on Route 85 in Hopkinton on Thursday night and struck a woman who got out of the other car, the Middlesex County District Attorney's Office wrote in a Friday news release.

The 26-year-old woman, Destini Decoff, died on Sunday from those injuries, her mother Tracy Decoff wrote on Facebook.

At some point during Thursday's confrontation, officials said, some of the occupants of her car got out, and Sweatt made a U-turn in his Honda Civic and hit the woman "at a high rate of speed."

Sweatt told police that Decoff and four men got out of their car and surrounded his, according to a police report obtained by CBS News. One had a knife, he said, and he shouted to responding officers that "they're trying to kill me!"

MASSACHUSETTS MAN VICIOUSLY BITES POLICE OFFICER'S HAND, DRAWS BLOOD AT CITY HALL: REPORT

Destini Decoff

Destini Decoff, 26, was sent flying in the air after Ryan Sweatt, 36, rammed her with his car in what police called an "apparent road rage incident." (Destini Decoff/Facebook)

The 36-year-old Milford resident was charged with assault and battery with a dangerous weapon causing serious bodily injury, operating to endanger and a marked lanes violation, according to the District Attorney's Office said, which could not be immediately reached to answer whether additional charges would be filed in light of her death. 

A witness told police that Sweatt "chose to turn around" and "knew what he was doing" when he made a U-Turn and hit Decoff with his Civic, according to CBS. Prosecutors said that surveillance footage of the scene affirmed the witness's account. 

"He turned around multiple times, and he could have just kept going," Brett Martin, who watched the scene unfold on Route 85 from Cornell's Irish Pub. "He chose to turn around. He knew what he was doing when he went towards that girl."

Martin said that the impact caused Decoff's clothes to fly off when she was thrown by the vehicle. 

"I saw her midair kind of coming down toward the street," Martin told CBS. "Her jacket must've been 20 feet away from her. However, she got hit, those clothes flew off." 

Martin said he ran over to the scene, grabbed Decoff's jacket and covered the bloodied woman.

HUNDREDS ACCUSE MASSACHUSETTS DOCTOR OF SEXUAL ABUSE, INAPPROPRIATE EXAMINATIONS

Destini Decoff

On Sunday, Tracy Decoff wrote on Facebook that her "firstborn child [and] best friend" had passed away. (Destini Decoff on Facebook)

Prosecutors said a police officer saw Sweatt speed away from the scene after the 6:30 p.m. incident, CBS reported. When police caught up to him, his windshield was damaged – he allegedly got out of the car screaming, "They're trying to kill me!" 

Sweatt told police that Decoff started the altercation by pulling in front of him and slammed on her brakes as he drove home from work, according to court documents. Then, he said, Decoff and four men got out of their vehicle and threatened him.

The District Attorney's Office did not specify whether Decoff had been driving before she was struck.

Following the District Attorney's Office announcement, Decoff's mother wrote on Facebook that Sweatt was "charged with everything he should've been." 

"She was in the car with friends when the car behind them was riding their bumper," the mother wrote. "Car pulled over, they got out of the vehicle and that car tried to run them over." 

JENNIFER AND JAMES CRUMBLEY TO BE SENTENCED IN SON'S MICHIGAN SCHOOL SHOOTING

Destini Decoff

Decoff suffered two collapsed lungs, a brain bleed, a slew of broken bones and extreme facial disfigurement in the attack, her mother said. (Destini Decoff/Facebook)

Decoff's mother wrote on Facebook that the woman had part of her skull removed to accommodate a brain bleed and was put on a respirator due to two collapsed lungs after she was mowed down in Hopkinton last Thursday.

With a broken rib, shoulder and tibia, along with facial disfigurement that required plastic surgery, the elder Decoff wrote that her daughter was "literally injured from head to toe." 

Last Friday, Decoff's mother wrote that she "hop[ed] that mf burns directly in hell" with "every ounce of [her] being." 

On Sunday, she wrote that her "firstborn child [and] best friend" had passed away. 

CLICK HERE TO GET THE FOX NEWS APP

Cornell's Irish Pub

The ultimately-fatal road rage incident took place on Route 85 near Cornell's Irish Pub, pictured. A witness told reporters that Decoff's jacket landed 20 feet away after she was sent flying in the air. (Google Maps)

Sweatt entered a not-guilty plea, according to court records, and is scheduled to appear in Framingham District Court on April 10. His attorney could not immediately be reached for comment.