A grand jury has begun hearing evidence in the 2016 drive-by shooting death of a Minneapolis toddler, the latest development in a case that shocked and infuriated many residents nearly three summers ago, but remains officially unsolved.

A man who police and prosecutors have long maintained fired the bullets that struck 2-year-old Le’Vonte King Jason Jones and his infant sister is set to appear before the secret panel this week to answer questions about the killing. The man, a rival of the siblings’ father, was one of two people arrested soon after the van they were riding in was shot up on a North Side corner.

But both suspects were later released, with prosecutors citing a lack of evidence to warrant charges. The Star Tribune generally does not name suspects who haven’t been charged.

The 33-year-old man who is the focus of the grand jury probe has long maintained his innocence in the slaying — which became a symbol of the indiscriminate violence plaguing parts of the city — even as his name popped up in news accounts and court documents as the prime suspect.

Le’Vonte was fatally shot on July 15, 2016, when the van he was riding in pulled up next to a black Chevy Impala at the corner of N. Penn and Lowry avenues, and someone in the car fired twice inside, police said. In response, they said, Le’Vonte’s father, Melvonte Peterson, returned fire as he whipped the van around the corner and sped away, driving the children to a hospital where Le’Vonte, who was struck in the chest, was pronounced dead. His 15-month-old sister was grazed in the leg and survived.

The motive for the shooting hasn’t been disclosed. Chuck Laszewski, a spokesman for the Hennepin County Attorney’s Office, declined to comment on the specifics of the case, saying, “Minneapolis Police and the Hennepin County Attorney’s Office have been working diligently on the case since the tragic shooting occurred.”

Asked for a comment, police spokesman John Elder replied in a text: “No comment from us as the grand jury convenes.”

Prosecutors at the time argued that Peterson’s actions had unnecessarily endangered his children’s lives, charging him with murder, manslaughter and neglect. But a judge later threw out the murder charges, saying that holding him responsible for Le’Vonte’s death “defies common sense.” He was sentenced to five-plus years in prison after being convicted of a weapons charge and is scheduled for release in November after serving a little more than two years.

In the meantime, homicide detectives continued to follow other leads, with only marginal success. Court filings show that witnesses and Le’Vonte’s father gave contradictory statements to police about who was involved in the shooting. A woman who had been in the van with Peterson before the incident reportedly offered one version of what happened to her friends, then told police something different.

After months of dead ends, the case heated up again last year after investigators reinterviewed several witnesses who had been with the suspect on the day of the shooting, the filings say.

One of the witnesses who had been with the suspect throughout that day told police that the suspect was the shooter, according to the filings. Another man who saw the suspect afterward claimed to have overheard the man say that he’d just been involved in a shooting.

The case took another turn in January when homicide detectives obtained a “reverse location” search warrant for the cellphone numbers of the suspect, Peterson and two witnesses. Viewed with skepticism by privacy advocates, the method gives police location data for all cellphones in a particular time and place.

Detectives were trying to establish whether the suspect was in the vicinity of the shooting scene when Le’Vonte was killed, and to corroborate that the witnesses were with him when they said they were.

While officials have given no indication a grand jury has been convened in the case, prosecutors last month filed a writ of habeas corpus — used to secure the release of a prisoner to appear in court — “in the matter of the death of Levonte King Jason Jones.”

The suspect is now expected to be called to answer questions from the panel, which will decide whether there is enough evidence to indict him. The proceedings are held in secret. He is currently serving a 17-year federal prison sentence for illegally possessing a firearm after authorities raided a house that he frequented and recovered four guns, synthetic marijuana and drug paraphernalia. Lab tests found the man’s DNA on one of the weapons, authorities said.

At his sentencing, the man pleaded for leniency, saying his arrest in Le’Vonte’s death was a case of mistaken identity and that the ensuing news coverage and the pressure of police scrutiny had been a nightmare for him and his family.

LeShae Jones, the toddler’s mother, said she has been frustrated by the lack of information authorities have given her about the investigation. She learned only recently that at least one of the homicide detectives assigned to the case has retired.

“They don’t return my phone calls, so if I don’t catch them … they don’t answer my phone calls,” said Jones, who has not been asked to testify before the grand jury.

And while the bullet wound on her daughter Melia’s leg has healed, she still carries the mental scars from an incident she barely remembers, LeShae says. Therapy has helped, she says, but Melia is shaken by loud noises and prone to outbursts of anger.

“Her nightmares come and go,” she said of her daughter. “When Melia started asking me about her scar, started asking me about [Le’Vonte], me being a young, dumb mom I told her about what happened.”

In many unsolved cases, police believe they know the killer’s identity, but can’t convince witnesses to testify or lack the physical evidence to prove it, according to Richard Edinger, a retired Minneapolis police detective.

“They’re always there, the ones that you didn’t get solved or get charged,” said Edinger, who spent more than 14 years in homicide. “You think about them, you think about the victims and the victims’ families.”