The RCMP has no record identifying who ordered police to abandon plans for a criminal investigation into the 2020 downing of Ukraine International Airlines Flight PS752, despite an internal proposal that argued Canada should conduct its own probe because of the large number of Canadian victims.A newly released report by the National Security and Intelligence Review Agency (NSIRA) found the RCMP never formally documented its decision to cancel the proposed investigation into the missile attack that killed 176 people, including 138 Canadian citizens and permanent residents."The RCMP did not create any contemporaneous record which formally documented the decision," the watchdog said in its March 19 report.The review was launched after complaints from four families of Canadians killed when Iran's Islamic Revolutionary Guard Corps shot down Flight PS752 shortly after takeoff from Tehran on Jan. 8, 2020.According to the report, RCMP officials moved quickly after the attack to pursue a Canadian criminal investigation.On Jan. 22, investigators proposed deploying officers to preserve evidence and interview witnesses with firsthand knowledge of the incident, arguing Canada had jurisdiction because of the large number of Canadian victims.Five days later, RCMP officials met with representatives from the Department of Justice and the Public Prosecution Service of Canada after drafting a detailed investigative plan."The RCMP's expertise in obtaining information to an evidentiary standard could allow the Canadian government to provide victims' families with a factual sequence of events to explain the crash of PS752," investigators wrote at the time.The proposal also argued it was "imperative to determine what actually occurred, independently from open-source reporting and the Iranian narrative," saying a criminal investigation could establish whether individuals or institutions bore responsibility and provide Canadians with verified facts.Despite those recommendations, the investigation never proceeded..Instead, the report says responsibility for the criminal investigation remained with Ukrainian authorities.NSIRA said it found no evidence the decision was motivated by political interference or conflicts of interest."There is no evidence to support the complainants' allegation that the Commissioner or any other RCMP members were motivated by political considerations or a conflict of interest," the report concluded.However, the review notes the decision came shortly after then-prime minister Justin Trudeau met Iranian Foreign Minister Javad Zarif on Feb. 14, 2020, during the Munich Security Conference.Twelve days after that meeting, the RCMP informed Global Affairs Canada by email that it would not proceed with a domestic criminal investigation."The RCMP will not be launching a formal domestic investigation into the downing of PS752," the email stated. "The decision was taken based on advice provided by the Department of Public Safety and considerable internal work and discussions."The review does not identify who ultimately made the decision or who instructed the RCMP to stand down.No criminal investigation has concluded into the attack.Iran's final report, released in 2021, concluded the airliner was shot down accidentally after air defence personnel allegedly misidentified the Boeing 737 minutes after takeoff. Families of the victims and several governments, including Canada, have rejected Tehran's explanation as incomplete.