The police officer who shot and killed a 19-year-old man in South Carolina threatened to blow his head off before firing, and another officer gave the teen’s lifeless body a high-five not long after he was killed, according to a lawsuit filed by the teen’s family.

The lawsuit contains a number of new details about the killing that are difficult to verify because state agents and a prosecutor reviewing the case have not released dashboard camera video or other documents. The prosecutor is trying to decide whether Lieutenant Mark Tiller should be charged in connection with the shooting.

The suit filed on Monday gives a detailed account of what happened from the family’s perspective. Family lawyer Eric Bland said they talked to the woman in the car with Zachary Hammond when he was killed, looked at private surveillance camera footage and did a private autopsy.

Hammond was killed on 26 July after taking Tori Morton on a first date. The couple got ice cream at McDonald’s, then drove to Hardee’s so Hammond could get a hamburger, according to the lawsuit.

Seneca police said they were waiting at the Hardee’s after an undercover officer arranged a drug deal with Morton. As officers pulled up to Hammond’s car with lights flashing, he accelerated to leave, authorities said.

Tiller said in statement issued by his lawyer that he thought Hammond was threatening to run him over and fired twice to protect himself. Hammond’s family said the autopsy showed the teen was shot in the side and the back, proving the threat had passed.

The lawsuit also seems to indicate there was a pause between the first and second shots, saying Hammond turned toward his date and stared after the first shot. The second shot killed Hammond, according to the private autopsy.

A small amount of marijuana was found on Morton and a bag with a small amount of white powder was found on Hammond, according to Seneca police. Morton was charged with misdemeanor drug possession.

After paramedics determined Hammond was dead, his body was left on the ground for 90 minutes where it was bitten and stung by ants. A second officer gave the lifeless teen’s body a high-five sometime after other investigators arrived, according to the lawsuit.

The family said they filed the suit in part to try and force authorities to release the dashcam video and other information. Solicitor Chrissy Adams and state investigators have refused, saying the case is still open.

The lawsuit begins with an introduction about the shooting and says: “‘I’ll blow your [expletive] head off,’ were the last words heard by Zachary Hammond.”

Adams said she will not decide whether Tiller faces charges until state and federal investigators answer some more questions and the state supreme court rules on another lawsuit from Hammond’s family asking her to be removed from the case because she works with the officers in the Seneca police department and other local agencies.

A public relations firm hired by Seneca did not immediately respond to questions about the suit.