Silence Jones is an agent with the Watchers.
That organization is described by the man who recruits Jones to be a member of the team as being "an underground operation to right wrongs, to dole out justice to people who have escaped it. A secret group hidden in plain sight, watching it all, monitoring the government's actions - local, state, and federal, even foreign affairs, things like CIA operations. When someone eludes the justice they so sorely deserve, we go in and administer that justice. Usually as a death sentence".
Jones is shown that the hierarchy of the Watchers consists of Captains, defined as the 'big guns', of which there are only a few of them and they all work in government positions. Beneath them are the Prefects, also members of government. It is the job of this group to monitor the next lower group called the Specialists as well as the group referred to as the Assets.
Assets are the one who get their hands dirty. "All of the fact-finding and resource-management of the Specialists; all of the leadership of the Prefects; all of the decision-making from the Captains ... eventually it all boils down to field work carried out by assassins. We call you Assets because, I'll be frank, you don't have a high survival rate. You folks are tools used to get the job done. If you live, super!, but statistically speaking, the odds aren't great".
Determining eligibility for someone to become an Asset is quite interesting and is further explained in the first recorded adventure which describes why the man who would become Jones is offered his position.
I say 'would become' because before he was became an Asset, Jones was Jake Rowe, a policemen in Pensacola, Florida. He had been so for just over a year before a chance came to go undercover to infiltrate one of that city's most powerful crime families. His job was obviously to work his way deeper into the crime family to better be able to bring it down. Unfortunately he got deep enough to meet and fall in love with the daughter of the crime boss, a young woman named Cecelia. And he got deep enough to make an enemy out of a higher-up in the organization.
It is when a revolt inside the group results in considerable mayhem and immense personal misery to Rowe/Jones that his life will change drastically. He should have died, a victim of that trouble, but instead survived a particularly horrendous beating that left his face terribly disfigured and his throat all but destroyed.
Surgery would restore his face, making him actually better looking than he had been, but the damage to his throat was too much to repair. Now every word spoken is a terribly painful one to him and invariably unsettling to those hearing it. Since his old life was gone and a new identity needed, he chose the strange but oddly appropriate new first name of Silence.
He now works solely as an Asset for the Watchers, codename Suppressor, meting out the punishment determined by the Watchers on whomever they feel deserve it. And that punishment is usually death.