Video purports to show deadly encounter between Georgia teen and deputies who used a Taser on him

— -- Newly-released dashcam video purports to show the moment an 18-year-old Georgia man was killed by law enforcement deputies who deployed stun guns on him during a 2015 encounter.

In the early morning hours of Aug. 31, 2015, Nicholas Dyksma was driving a Toyota pickup truck on U.S. Highway 27 while being pursued by police in Columbus, Georgia, and crossed into Harris County, according to a civil lawsuit filed Feb. 14 in U.S. District Court Middle District of Georgia against members of the Harris County Sheriff's Office who were involved in the incident.

After Harris County deputies took over the pursuit, they were able to stop the truck by placing stop sticks around the seven-mile mark on the highway, near Hamilton. Once the truck was immobilized, at least one of the deputies allegedly smashed a car window and "forcibly removed" Dyksma from the car, according to the lawsuit.

The deputies then used a Taser to force Dyksma to the car to be handcuffed, "pinning him to the ground with the weight of their bodies, and continued to do so even after he was handcuffed," according to the lawsuit. The officers' combined weight then allegedly cut off Dyksma's air supply "so that he was unable to breath," and the officers "did not stop applying pressure on his airway until after he lost consciousness."

Once the deputies realized that Dyksma was unconscious, they stopped applying pressure but "simply stood there and made no attempt to resuscitate him," even though at least one of them were trained in CPR, according to the lawsuit.

"It was not until the ambulance arrived some ten minutes later that Defendants made any attempt to perform CPR on Nicholas, and by then it was too late to revive him," the lawsuit states.

In the video -- obtained last year by the Dyksma family's attorneys from authorities via the Georgia Open Records Act, but exclusively released this week by ABC affiliate WSB-TV in Atlanta -- four deputies can be seen approaching the truck with weapons drawn before they pull Dyksma out through the passenger side. They then appear to restrain Dyksma on the ground for several seconds.

Dyksma's mother, Tammy Dyksma, told WSB-TV that she believes the deputy should be "punished." The family's attorney, Craig Jones, told WSB-TV that Dyksma was sleeping in his truck prior to the police pursuit.

"They woke him up and startled him, and he drove away," Jones said.

Dyksma was pronounced dead at a local hospital, according to a death certificate.

The Georgia Bureau of Investigation blamed the deputies' actions for Dyksma's death, stating that the Taser and compression of his neck and torso were to blame, as well as methamphetamine intoxication.

Dyksma's cause of death was determined to be "sudden death during an altercation with law enforcement, after deployment of an electroconductive device, with prone positioning, compression of the neck and torso, and acute methamphetamine intoxication," according to an autopsy report by filed by the Georgia Bureau of Investigation filed on Dec. 11, 2015. His death was also ruled a homicide.

The deputies "knew or should have known that the continuous application of pressure to his torso could cause Nicholas Dyksma to asphyxiate and die, but they did so anyway and did not stop until he was dead or near death," the lawsuit alleges, adding that each of the deputies "acted unreasonably" in causing or contributing to Dyksma's death.

The lawsuit alleges that there was "no justification" for the "unreasonable" life-threatening force used against Dyksma because "he did not pose any immediate threat of death or serious bodily harm to" the deputies.

Three of the deputies named in the lawsuit -- Sgt. Joe Harmon, Deputy Heath Dawson and Deputy William Sturdevant are still with the department and assigned to regular duty, a spokesperson for the Harris County Sheriff's Office told ABC News. Deputy Tommy Pierson was terminated from the department in 2016, according to the sheriff's office, for unrelated reasons.

The investigation is ongoing, Harrison County District Attorney Julia Slater told ABC News, but there are no charges or pending charges against the deputies at this time.

The Hamilton-based attorney representing the four deputies in the civil case, John Taylor, declined to comment on the case at this time due to the ongoing litigation.

A spokesperson for the Georgia Bureau of Investigation declined to comment on the case since it is now being handled by the Harris County District Attorney's office.

The family is seeking a jury trial and damages in an amount to be determined by the jurors, according to the lawsuit. They are also seeking attorney's fees and reasonable expenses of litigation.