The mother of a 15-year-old boy with autism who was fatally shot by police in the family's Calumet City, Ill. home earlier this year has filed a lawsuit against the Chicago suburb and the officers who killed her son.

Danelene Powell-Watts, mother of Stephon Watts, has named William Coffey and Robert Hynek -- two Calumet City police officers -- as defendants in the lawsuit, filed Wednesday in Cook County. Powell-Watts previously filed a lawsuit in March in order to obtain the names of the two officers involved in the shooting death of her son.

The six-count suit claims that, though Calumet City police say the shooting death was justified as self-defense and Cook County State's Attorney Anita Alvarez chose not to charge their department with any wrongdoing, the officers "intentionally and forcibly caused unconsented harmful contact" to Stephon, leading to his wrongful death. Powell-Watts is seeking an unspecified amount of damages.

Stephon Watts, who was diagnosed with Asperger's syndrome when he was 9, had had 10 previous interactions with the suburb's police department over the past two years. The run-ins included at least one incident where police discharged Tasers to subdue him.

On Feb. 1, Stephen Watts, Stephon's father, had reportedly called police after arguing with his son, who didn't want to go to school, having been instructed by social workers that Watts should be handled by authorities when agitated.

Police say they found Watts armed with a knife in the basement of his parents' home. When one officer sustained a defensive wound to his left forearm, two other officers on the scene fired their weapons. Steven Watts says his son was shot once in the leg, and then again in the head.

(Scroll down to watch a previous report on Stephon's shooting death.)

Watts' family has adamantly spoken out against the fatal shooting.

"There was no reason they had to kill him," Powell-Watts told the Northwest Indiana Times of her son's death during a community protest of the incident in February.

Stephen Watts spoke of his son during a panel discussion sponsored by the Rainbow PUSH Coalition, the International Socialist Organization and the Campaign to End the Death Penalty at Grace Place in the South Loop earlier this month.

"My baby was taken from me, he was murdered by Calumet City police officers," Stephen said at the panel. "My baby's gone, he's six feet under, he's not coming back and there's nothing I can do about it."

As April is Autism Awareness Month, the Tinley Park school Stephon attended is preparing to honor the 15-year-old during a balloon launch aimed at spreading increased awareness and understanding of autism Friday, TribLocal reports.

Asperger's syndrome interferes with social skills, but sufferers often have normal to high intelligence.

Stephon's family has set up a website -- titled Justice for Stephon Watts -- to share updates about the case going forward.