BATON ROUGE, La. - A settlement agreement has been reached in a family's lawsuit over the fatal shooting of a 6-year-old autistic boy during a traffic stop by law enforcement in Louisiana.

U.S. District Judge Dee Drell dismissed the suit late Thursday as the parties worked toward a final agreement. Drell's order says he can reopen the case if the settlement isn't "consummated" within 90 days.

Steven Lemoine, an attorney for relatives of the slain child, Jeremy Mardis, said in a text message that he can't disclose the terms.

Mardis was strapped into the front seat of his father's car when two deputy city marshals in Marksville opened fire on the vehicle after a November 2015 chase, killing the boy and critically wounding his father, Christopher Few.

One deputy, Derrick Stafford, was convicted of manslaughter last March and sentenced to 40 years in prison; the other, Norris Greenhouse Jr., pleaded guilty last September to negligent homicide and was sentenced to 7 1/2 years in prison.

The Nov. 3, 2015, shooting was captured on video by a police officer's body camera. Defence attorneys claimed Stafford and Greenhouse acted in self-defence, but prosecutors said the video shows the deputies firing on Few's car from a safe distance while his hands were raised inside the vehicle.

The family's 96-page lawsuit, filed in October 2016, claims Marksville city officials had failed to properly train the deputies on the use of deadly force. The suit also says the officers involved did nothing to stop the boy's bleeding or alleviate his suffering, even after one of them found a pulse on the child.

"Sadly, Jeremy was left to suffer — and die — while the officers casually searched for gloves," the suit said.

The boy's father and two other relatives sued the town of Marksville and its city court, Avoyelles Parish, Marksville City Marshal Floyd Voinche Sr., and the officers involved in the shooting.

Drell's order doesn't specify whether all of the parties are involved in the settlement agreement.

Court filings show Stafford and Greenhouse were ordered to be brought to Alexandria this week for a two-day settlement conference before a federal magistrate judge.

Attorneys for Avoyelles Parish and Stafford declined to comment Friday.

Stafford was a Marksville police lieutenant. He and Greenhouse, a former Marksville police officer, were moonlighting as deputy marshals.

Marksville's deputy marshals were part-timers who normally serve court papers, but Voinche had them stopping cars, writing traffic tickets and going on patrols for months before the shooting because the City Council slashed the city court's budget at the recommendation of Mayor John Lemoine.

The city court, which presides over traffic citations, sued the city over the deep cuts in July 2015, saying Marksville had stopped paying the salaries of Voinche, Judge Angelo Piazza III and the court's clerks.

The family's lawsuit calls the shooting a "barbaric and excessive use of deadly force" that fit a pattern of behaviour unpunished by town officials who supervised the two deputies.

The deputies' lawyers claimed Few drove recklessly while leading officers on a 2-mile (3-kilometre) chase and then rammed into Greenhouse's vehicle as he was getting out of it, before he and Stafford opened fire.

Stafford testified at his trial that he didn't know the boy was in the car and didn't see Few's hands in the air. But he said he shot at the car because he feared Few was going to back up and hit Greenhouse with his vehicle.

Few is white, as was his son. Stafford and Greenhouse are black. Their defence attorneys accused investigators of rushing to judgment, arresting the officers less than a week after the shooting. One of Stafford's attorneys questioned whether investigators would have acted more deliberately had the officers been white.

News from © The Associated Press, 2018