Though it might seem otherwise, Tracy has no more alleged molesters, child pornographers and sex offenders than any other city, police say.

But what Tracy does have is a pair of full-time cops whose job it is to hunt for child predators and other sex criminals and a police department that willingly publicizes arrests.

In the span of about six weeks, four men have been arrested and accused of possessing child porn, having sex with kids or molesting women.

In the city’s latest case, the arrest on molestation and child porn charges of 39-year-old Jesse Llorente III, a substitute teacher, came about when school officials went to police.

Yet Lt. Ken Bunch and Assistant Chief Rick Golphin are quick to give credit to detective Nate Cogburn, who they say brings tenacity to his cases.

Bunch called Cogburn, who’s in his late 20s, a "millennium generation" investigator with a dogged ethic and deft computer skills that allows him to scan the Internet for child predators.

It’s computer savviness on which Cogburn is making his reputation as a detective, in part because many of his arrests get heavy publicity. Dozens of television cameras were at a Thursday press conference in the wake of Llorente’s arrest, for instance.

Even Llorente himself immediately recognized Cogburn as the department’s child porn cop, Golphin said.

Cogburn was tasked with tracking child sex crimes in the middle of 2007 with Octavio Lopez. Cogburn and campus policeman Chuck Baker pitched the idea of pursuing child predators on the Internet. They convinced the department to buy software that can track people who share child pornography and that can mask the police department’s Web IP address.

Cogburn spends part of his job pretending to be a kid online, setting up phony MySpace accounts to pose as girls in order to catch the men who try to lure them into sex.

In late February, the department announced the arrest of James Hagelston, 41, on suspicion of possessing child pornography.

Cogburn alleged that he found Hagelston using child porn-tracking software, and authorities allege they found movies on his computer that show girls younger than 10 having sex with adult men.

He has pleaded innocent, but the charges triggered shock waves because Hagelston was well-known in town, had once coached a girls softball team and had a job that routinely sent him into schools.

A third man, 31-year-old transient Anthony Cummings, is now in custody on rape and other sex charges involving a 4-year-old girl.

Bunch and Golphin also give credit to Cogburn for months of investigation that led to the Feb. 4 arrest of plastic surgeon Peter Chi, who faces 11 counts for molesting women patients and at least one employee.

But as Cogburn’s stature as a skillful detective grows, so too does the image of Tracy as some sort of magnet for alleged child sex and pornography offenders.

That’s because police department officials say they want to publicize alleged sex crime cases in which they believe more victims will come forward once they are aware a suspect has been arrested.

And Golphin believes the publicity not only creates an atmosphere that allows victims to safely come forward to expose abuse, but it also puts fear in men who try to hide their sex crimes and sends a message that they will be caught.

Chi is expected to be charged with 30 more counts of molestation because additional women came forward once they saw he was arrested, police and other officials have said.

Bunch and Golphin lament the fact that high-profile arrests, in an indirect way, cast suspicion on thousands of perfectly fine men who coach youth sports and teach kids, men who are the overwhelming majority.

Child predators are rare, police say, though they are often lured by jobs where they can interact with kids.

The public, Golphin says, "should feel safer that we’re arresting these guys."