A Kentucky deputy who witnesses say jumped onto the roof of a 19-year-old girl's car and opened fire on her will not be indicted in the girl's death.

Samantha Ramsey was killed by Boone County deputy Tyler Brockman as she left a party in April. Now, a Boone County grand jury has decided not to indict Brockman, who has always maintained he acted in self-defense, the Cincinnati Enquirer reports.

Footage from the dash cam of Brockman's car can be seen above.

In a statement to his supervisors, Brockman said he tried to stop Ramsey from driving away from the party so that he could see if she was intoxicated.

Brockman told his boss that Ramsey then took a "left turn" and ran into him, forcing him up onto the hood of her car.

Brockman said Ramsey sped up and, "At this point Deputy Brockman knew the operator, Samantha Ramsey was about to kill him," the statement said. "Deputy Brockman in reaction to the deadly force brought against him, drew his Glock 22 Service weapon and fired what he believed to be 3 shots (turned out to be 4) through the driver window."

In a statement sent to The Huffington Post, Ramsey's mom, Brandi Stewart, expressed her disappointment in the grand jury's decision.

"Now, over six months after my daughter was shot to death by Deputy Brockman, the only thing I know for sure is that he will not answer for his actions and that in Boone County, you cannot indict a Boone County Deputy for shooting an unarmed 19-year-old four times in front of numerous witnesses," Stewart said.

She also said the investigation should have been handled by another law enforcement agency, rather than the sheriff's department.

"The Community's concerns regarding the Boone County Sheriff investigating one of it own deputies have been confirmed," Stewart said. "The investigation should have immediately been turned over to another police agency."

When the case was first reported, witnesses and the teen's family said Brockman jumped on Ramsey's car and fatally shot her.

"That's murder!” Ramsey’s friend, Gunnar Buemi told WLWT in April. “Justice needs to be done about this injustice."

The evidence report released in the case said Ramsey had a blood alcohol content of .12, over the legal limit for someone 21 or older to drive a car.