A few days before Christmas, 4-year-old Jassiah Clark fell into an abandoned sewer hole on vacant property next to his north Baton Rouge home and drowned.

Less than three weeks later, on Tuesday, police arrested the boy’s mother, Brittni D. Clark, saying she was negligent in her son’s death. And a few hours after that, Clark’s attorneys filed a wrongful death lawsuit on the boy’s behalf against the city-parish, claiming the companies hired by the city-parish to fill the sewer hole, which was about 20 feet deep, failed to do it properly, thus creating a dangerous and unmarked hazard next to the Clarks’ home.

The Police Department said Clark’s arrest was in no way connected to the lawsuit.

“This has nothing to do with any type of lawsuit against the city,” said Don Coppola Jr., a police spokesman. “This is a parent who has been negligent in their child’s whereabouts, not only this time, but for some time now.”

Police said Clark, 25, lost track of her son on a regular basis, including the night of Dec. 20, when Jassiah went missing. Clark told investigators she last saw her son about 5 p.m., about six hours before he was reported missing to police, when he went outside to play with some other children, according to a police report.

She and her boyfriend then watched a movie until about 8 p.m., and it wasn’t until after her sister returned to their Robertson Avenue home that Clark began to look for her son, the report says.

The mother told police “that it was not uncommon for Jassiah to be gone for several hours,” the report says.

The report also says Clark “has a substance abuse problem,” at least partly based on some text messages she sent in the days leading up to her son’s death, in which she requests “sticks” and “bars,” which the report describes as slang terms for drugs.

It wasn’t clear Tuesday whether Clark had ever been arrested, charged or convicted on any drug-related crimes. A search of 19th Judicial Court records did not indicate she has ever been accused of any such crimes.

However, Clark did spend a week in the East Baton Rouge Parish Prison in November on accusations she stole money from her father, who has dementia, according to an arrest report. Clark posted $42,500 bail on Nov. 26 and was released.

The police report regarding the negligent homicide arrest says investigators learned from unidentified neighbors that Clark regularly lost track of her young son.

“Detectives interviewed a neighbor who stated that it was not uncommon for Jassiah to show up at her residence by himself and stay for days at a time,” the report says.

A neighbor who spoke to a reporter said Jassiah and his 9-year-old brother often played outside for much of the day. The neighbor also said she didn’t know how often Clark checked on her children.

“I know a lot of people say that the kids were basically on their own sometimes,” the neighbor said.

Clark, 5676 Robertson Ave., Baton Rouge, was booked Tuesday into the Parish Prison on one count of negligent homicide. It wasn’t clear whether her bail had been set as of Tuesday evening.

Lewis Unglesby, one of Clark’s attorneys, discredited accusations that Clark was negligent in her son’s death, saying it was, as the lawsuit alleges, the negligence of the people hired to fill the deep hole that led to Jassiah’s death.

“There’s no basis for any charges against Ms. Clark,” Unglesby said. “She’s the victim of a terrible tragedy caused by the negligence of the people who dug the hole and failed to secure it.”

The suit says Grady Crawford Construction, of Baton Rouge, and CH2M Hill Inc., of Englewood, Colorado, were hired by the city-parish in September to fill the hole. The suit lists both companies, their insurance representatives, and the city-parish as defendants in the matter.

The suit alleges the hole was filled with “improper materials, which allowed the 20 foot hole to fill with water.”

During the massive hunt for Jassiah following the filing of the missing person report, searchers passed by the hole many times. One of the boy’s family members has said she saw a police officer nearly fall in.

It wasn’t until an officer with a flashlight at night took a closer look at what appeared to be a puddle that the hole was discovered.

“This child fell in the hole,” said Ruby Chambers, Brittni Clark’s mother. “Now it’s her fault? Nobody knew that hole was out there.”

Chambers described her daughter as a good mother who neither abused drugs nor neglected her child’s wellbeing. Chambers described the accusations made by police about her daughter as lies.

“She took care of him,” Chambers said. “Brittni loved Jassiah, and he loved his momma.”

Chambers said she believes police arrested her daughter only because of the pending lawsuit — an allegation the department flatly denied, citing the findings of the investigation.

“That child has gone through enough,” Chambers said of her daughter. “For them to come do that to her, it’s just not right.”

Follow Ben Wallace on Twitter, @_BenWallace.