Ontario's Special Investigations Unit (SIU) was tasked with investigating the circumstances surrounding the Toronto teenager's death. Toronto Police Chief Bill Blair indicated there would also be an internal review.
However, the province could conduct its own investigation if it is dissatisfied with the SIU's work, Andre Marin told CBC's Metro Morning shortly after the shooting.
The office's investigation would look at what direction Ontario's Ministry of Community Safety and Correctional Services provides police on de-escalating conflict situations.
Yatim, 18, died July 27 on a TTC streetcar.
A bystander captured a video showing the police standoff with Yatim. The video shows police firing nine shots. Officers also deployed a Taser after the shooting.
The Toronto police officer who shot Yatim was suspended from his job with pay days after the shooting.
Witnesses have said Yatim was holding a knife on the streetcar before police arrived on the scene.
Marin is set to announce his decision at 1 p.m. ET.