TORONTO

I hope they’re shaking in their boots.

Four years they’ve lived with this. For four long years, these witnesses to murder have failed to come forward and tell what they saw: A man being beaten. A man being run over. For nothing.

There were five other people in the 2004 black Ford Explorer that ran down Christopher Skinner in the early morning hours of Oct. 18, 2009. The alleged driver, Agustin Caruso, was finally arrested Wednesday and appeared at College Park courts Thursday charged with second-degree murder.

Wearing a black hoodie and grey sweatpants, the 23-year-old Etobicoke man looked remarkably unconcerned as he stood in the prisoner’s box and was remanded in custody until his next appearance Dec. 2. His father looked on, but refused to comment about the serious charge his son now faces.

The allegations against Caruso haven’t been proved in court and he has not yet been required to issue a plea.

He was ordered not to contact a list of people who the prosecutor said were witnesses and the subject of security concerns. He indicated that he understood and was taken away to spend the foreseeable future in jail — a place he may have believed he would never see.

What has Caruso been up to these last four years? It appears he’s been a student at Humber College and playing in an adult hockey league. Going about his life.

Five others are still going about theirs.

At a press conference a few hours earlier, Homicide Det.-Sgt. Stacy Gallant told reporters that this is not the end. “I can assure you there will be more arrests in the near future,” he said.

Skinner was 27, a good-looking guy with aspirations of becoming a lawyer like his dad. He had just left his sister’s 19th birthday party at a bar in the Entertainment District and was on Adelaide near Victoria trying to hail a cab when investigators believe he “inadvertently” brushed up against a passing black Ford Explorer.

For some inexplicable reason, that enraged the people inside and some of the male occupants jumped out and began viciously beating and kicking Skinner. And then, as he lay on the ground, they got back in the vehicle and drove directly over Skinner.

They left him there to die and sped away.

Four years have passed. They must have believed they were in the clear. There were annual police press conferences on the anniversary, as there was three weeks ago, with Skinner’s grief-stricken family members baring their souls, begging people to come forward. But still no identified suspects, no arrests. And the six involved kept their horrible secret and maintained their silence.

How do they live with themselves? How do they go about their daily lives knowing a family is suffering and the police have vowed not to rest until they bring the guilty to justice? Have they felt the pressure of conscience or fear?

What of the dynamics of this group? Are they still friends, swearing to keep quiet and protect each other at all costs? Or has the stress of sharing a crime torn them apart?

It may be sad, but not terribly surprising that the men involved in Skinner’s beating have refused to come forward and admit to their role in this senseless tragedy. Self-preservation, I suppose, would kick in even if they do regret what transpired that night.

But investigators believe there were also two women in the SUV that night who didn’t take part in the assault, yet refused to come forward as well. How have they withstood these years of emotional pleas from Skinner’s family? Have they no heart?

The day of reckoning, though, is near.

“I have some idea who the others are involved and who was in the vehicle and that is the avenue we are pursuing now,” Gallant warned. “I’m sure they’re aware I’m pursuing them.”

These cowards must be quaking now with fear as the puzzle is beginning to come together and the police are closing in. It’s only a matter of time.

“If it takes three more years, six more years, nine more years, eventually those responsible will be accounting for their actions,” Gallant vowed in 2012.

I hope they’re terrified.