A Toronto police constable charged with second-degree murder in the shooting death of Sammy Yatim will be arrested Tuesday based on an arrangement between Ontario's Special Investigations Unit and the officer's lawyer.

After Const. James Forcillo turns himself in to the SIU, he will remain in custody and then appear before a justice of the peace at the Old City Hall courthouse, the SIU announced Monday after an arrest warrant was issued.

Once he is in custody, Forcillo is eligible to apply for bail "at any time," the SIU said in a news release.

The police watchdog is not revealing the location of the arrest because Forcillo has received threats, the news release says.

A little more than three weeks after the shooting, the SIU announced the charge and arrest plan Monday, saying its director, Ian Scott, has "reasonable grounds" to believe that the officer committed a criminal offence. The SIU has not revealed any of its evidence.

It is extremely rare for a murder charge to be laid against a police officer.

After the charge was announced, Yatim’s sister, Sarah Ann Yatim, tweeted: “The SIU charged the cop with 2nd degree murder!!! Good morning JUSTICE.”

In a written statement released shortly after 4 p.m., the Yatim family said they were relieved by the SIU’s recommendation that the charge be filed.

“We have been waiting patiently and cooperating with the police investigation and want to hold accountable all those responsible for Sammy’s death,” the statement reads.

“Over 20 uniformed police officers were present and no one stepped forward to stop the gunshots or offer any mediation,” the release continues. “Moving forward we expect complete transparency and accountability.

“We want to work now to ensure that Sammy’s blood wasn’t wasted and to prevent any other families from enduring such a tragedy,” the statement adds.

The statement concludes with the family thanking the public for their support following the shooting.

Earlier, Toronto Police Association president Mike McCormack, who previously urged people not to jump to conclusions after watching a witness' video of the shooting, said the facts will emerge now that the case is going before the courts.

“We’re very disappointed obviously in these charges,” McCormack told CP24 reporter Cam Woolley. “We’re not surprised but what we do is we stand by due process, and now that we’re into this process the charges are going to be before the courts. Let’s see where the evidence leads and let’s start talking about evidence and truth and facts instead of people just jumping to conclusions and having a subjective test and applying their own theories.”

Yatim's family has been calling for justice since he was fatally shot on a TTC streetcar at Dundas Street West and Bellwoods Avenue early July 27.

The 18-year-old man was wielding a knife inside the empty streetcar when he was shot by Forcillo, who was standing on the street with other officers near the streetcar’s open front door.

In a cellphone video recorded by a witness, nine gunshots are heard during the encounter. Three shots are fired initially, followed by six more shots about five seconds later.

In the video, it appeared the six additional shots were fired after Yatim had already fallen to the streetcar's floor.

Police are heard repeatedly shouting “drop the knife,” and a male voice is heard apparently taunting the officers before the shots were fired. The sound of a Taser is heard after the gunshots.

Witnesses said the streetcar came to a stop and people rushed off when Yatim brandished a knife. Police arrived a short time later.

Public outrage

After the video was posted on YouTube and repeatedly shown on news broadcasts, public outrage erupted over the handling of the incident, along with allegations of excessive force.

The officer-involved shooting led to protests attended by hundreds of people at Dundas and Bellwoods, Yonge-Dundas Square and in front of police headquarters on College Street.

Forcillo, a married father of two young children, is suspended with pay, pending the outcome of the case. If convicted, a charge of second-degree murder carries an automatic life sentence with no chance of parole for at least 10 years.

McCormack said the officer is "devastated" by the charge.

“This has not been an easy process for him," McCormack said. "It’s been a lose-lose situation for everybody, including our members who have to go through this.”

McCormack said the incident impacts morale within the service, but his members are dedicated and professional officers who should not be judged as a whole because of the shooting.

“Don’t use a broad brush to judge policing,” McCormack said. “This is one incident. Let’s judge that based on the evidence and the facts.”

Toronto police declined to comment on the charge.

Reviews underway

In addition to the SIU’s investigation, Toronto police Chief Bill Blair is doing his own review to find out if the officers complied with the service’s policies, procedures and training, and Ontario ombudsman Andre Marin is reviewing the kind of direction the province gives to police for de-escalating conflict situations.

Retired judge Dennis O’Connor is assisting Toronto police in its review of its use-of-force guidelines while dealing with "emotionally disturbed" persons.

The SIU is an arm’s length agency that investigates reports involving police where there has been a death or serious injury.

Yatim family friend Joseph Nazar said he hopes no one else has to go through what the Yatim family is experiencing, as he called for changes to use-of-force tactics.

“Sammy wasn’t a combatant,” Nazar said, “He wasn’t a threat to anybody’s life. He was alone in that streetcar.”

@ChrisKitching is on Twitter. For instant breaking news, follow @CP24 on Twitter.