BALTIMORE — The Baltimore Police Department on Thursday introduced members of a panel created to independently review the baffling death of a Baltimore detective fatally shot with his own gun a day before he was set to testify before a federal grand jury probing dirty cops.

At a news briefing, Police Commissioner Darryl DeSousa stressed that "everything is going to be reviewed" by the seven-member independent review board, including whether they believe evidence points to a homicide, a suicide, an accidental injury or even "something internally within the department."

"They're going to look at everything. They're not going to keep anything unturned," said DeSousa, a Baltimore police veteran who took over leadership of the city's force earlier this year.

The unsolved case remains a homicide investigation led by Baltimore detectives. Investigators have said detective Sean Suiter was attacked in November 2017 while investigating a 2016 triple homicide with his partner in a high-crime neighborhood in West Baltimore. The medical examiner's office ruled the death a homicide.

But in the roughly five months since Suiter was shot in the head with his own gun the day before he was to testify for a grand jury investigating police corruption, his death remains a puzzling whodunit and conspiracy theories have flourished. There has been a $215,000 reward for months, but nobody has been charged.

Authorities have repeatedly said there's no evidence to suggest Suiter's scheduled testimony in the federal investigation led to his death. And in late December, the FBI declined to accept Davis' request for federal agents to lead the Suiter investigation, sending a letter to police saying they believed it would be "prudent" for city police to continue leading the inquiry.

DeSousa disclosed last month that an independent panel would examine Suiter's death in hopes outsiders can shed light on what police have described as a random attack by an unidentified suspect. He told The Associated Press they needed a "fresh set of eyes on it."

Former Police Commissioner Kevin Davis, who was fired by the mayor in January, told reporters last year that Suiter approached a "suspicious" man in a vacant lot between row houses, leading to a violent confrontation in which he was shot with his own gun. His partner can be seen on private surveillance video taking cover across the street, Davis had said.

But responding to a reporter's question on Thursday, DeSousa said he did not know the origin of the few vague details about the lone attacker — identified as an African-American man in a black jacket with a white stripe.

"I don't know where exactly it came from," DeSousa said.

On Thursday, DeSousa said he's had lunch several times with Suiter's grieving wife, who has stayed quiet since his death.

The independent review board will be paid for with roughly $150,000 from the police budget. It is being led by James "Chips" Stewart and James "Chip" Coldren, both members of CNA, a nonprofit research firm based in Arlington, Virginia. The seven-member panel includes two retired Baltimore homicide detectives.

"This is a complicated case and we're going to take a thorough look," said Stewart, estimating their work and various recommendations would take roughly six months to deliver.