On Monday, the Suffolk County District Attorney's office in Boston released video footage that captured Usaama Rahim's fatal encounter with officers and an FBI agent on June 2.
The clip from the video appears to show a physical altercation between Rahim and authorities. Rahim is highlighted in the video with a yellow ring.
Here is a closer view of the fatal shooting.
On June 2, a Boston joint terrorism task force was tipped off that Rahim was headed to a bus stop with an intent to commit violence.
The task force, composed of Boston police officers and FBI investigators, had been monitoring Rahim for his possible affiliation with ISIS. They suspected he had been plotting to inflict harm officers.
Members of the task force were not in uniform when they approached Rahim near a bus stop for questioning that Tuesday.
According to Boston Police Commissioner William Evans, the officers who closed in on Rahim knew that he was carrying a "large military knife," though it's unclear when they first actually saw the weapon. That remains under investigation.
Boston police showed Rahim's family the video on June 4, and Suffolk County district attorney Daniel Conley also showed it to several community leaders before its public release. Conley said the preview was intended to address skepticism about the tactics employed by authorities and a rumor that Rahim was shot in the back.
Critics have questioned whether the lethal force was justified.
"No one could have foreseen what unraveled," Evans said. "I think he was intent on getting a boy in blue. I don't think at this point he was going to go down very easy."
Evans said that the alternative non-lethal uses of force available to the officers when they apprehended Rahim is still being investigated, and restated that Boston police officers do not carry Tasers.
Some raised the question of whether or not officers considered the presence of the school bus, which was in the parking lot when the shooting took place. Evans did not comment directly on that consideration, but said that the "officer used restraint."
