The family of Antonio Zambrano-Montes, the 35 year-old Mexican immigrant who was gunned down this month by three officers in northwestern agricultural city of Pasco, Washington, have asked for an independent autopsy, local officials said Thursday.

Work by an independent pathologist could begin as early as this weekend, according to press reports. The initial official autopsy has already been completed, but Franklin County coroner Dan Blasdel is currently awaiting the toxicology report, which will take between six and eight weeks, before releasing the autopsy’s finding.

Zambrano-Montes’ death last Tuesday in a hail of bullets fired at close range by three officers, since identified as Ryan Flanagan, Adam Wright and Adrian Alaniz, was caught on bystander video, provoking mass outrage. Police allege that he had been throwing rocks at traffic and officers. Police initially insinuated that he may have been “armed with a rock” when he was killed, but have since admitted that he was unarmed.

The video clearly shows Zambrano-Montes fleeing on foot before being cornered on the opposite sidewalk by police officers who then shoot him at least ten times while he backs away with his hands up.

Zambrano-Montes, who was born in Mexico but had lived in Pasco for ten years, had a history of mental illness and had been battling with depression since being separated from his two teenage daughters. In the last months of his life he experienced a run of bad luck, including a house fire that he had to be rescued from and an injury due to a fall at his job as an apple picker. A worker at a homeless shelter blocks away from the intersection where Zambrano-Montes was killed confirmed to the Guardian that he had stayed there for about four days, just “a couple” of days before he was killed.

The family has also filed a massive $25 million lawsuit against the city, alleging racial discrimination and improper use-of-force training by the Pasco Police Department. Zambrano-Montes’ death is the third police killing since July in Pasco, a majority Latino city with large numbers of immigrants working as farm laborers.

The complaint argues that the “execution style” killing of Zambrano-Montes stems from the decision by the Pasco Police Department to retain “officers who had a proven history of violation of civil rights.”

Officer Ryan Flanagan, one of the officers who killed Zambrano-Montes, had also been named in a previous lawsuit alleging improper use of force training in 2012. The city settled that case for $100,000.

Police and government officials are seeking to rein in public anger while preparing an official whitewash of the killing, following a pattern firmly established after the murders of Michael Brown and Eric Garner. Despite conclusive photographic evidence, viewed over one and a half million times on Youtube, of officers gunning down an unarmed man in cold blood, police are dragging out their investigation as long as possible.

On Thursday, a spokesman for the special investigative unit (SIU) of the nearby Kennewick Police Department, which is leading the official investigation, refused to tell reporters how many bullets police actually fired at Montes. At the same time, he was quick to defend the killer officers and attack Montes, calling his behavior “not normal” and declaring “none of you would throw rocks at cars.”

Pasco Police Chief Bob Metzger defended the officers in a press conference the day before, declaring that “We always stand behind our officers unless they are proven [wrong]. We are at this point doing a thorough investigation. If the officers are wrong they will be dealt with accordingly. If they are not wrong, that will also come out.”

On Wednesday, Blasdel announced the unusual decision to hold a coroner’s inquest, in the interest of “transparency.” According to Blasdel, the inquest will not be held until after the SIU investigation and the release of Montes’ toxicology tests, both of which are expected to take at least two months. It will consist of a jury of six people, including three Latinos, which will hear the country prosecutor explain the results of his investigation, after which they will decide whether the shooting was justified. The jury, however, will have no power to indict the officers, which decision will remain wholly with the prosecutor’s office.

The main goal of the inquest is to provide some semblance of legitimacy to the likely decision not to prosecute the killer cops. Blasdel told reporters “The reason that I set up the inquest is because there’s a lot of Hispanic people that are pointing and saying this is cops investigating cops and so it’s biased. That’s not fair. So I want to make sure that’s brought out to the public, that investigation is transparent and everyone can see that it’s not bias.”

The killing, the latest in a string of high-profile police murders, has proposed mass popular outrage in the area and throughout the country. On Saturday several hundred people demonstrated in Pasco’s Volunteer Park, chanting and holding up signs with slogans such as “I can’t breathe” and “hands up, don’t shoot,” alluding to previous police killings in Ferguson and New York City.