As dusk falls and lights flick on amongst a hodgepodge of restaurants, nail salons and dance clubs overlooking this Cambodian capital's waterfront, tuk-tuk taxis whisk past a reality that emerges nightly in the shadows along the street.
"In the dark, that's where the guys will come to groom. Like there," says Brian McConaghy, beckoning behind him at two men in creased floral prints, sandals and berets. "Unpleasant sight. Those kind of guys creep me right out."
While there is nothing overtly criminal taking place, the former RCMP officer has investigated enough child sexual exploitation cases to know there's something very wrong. Mr. McConaghy is in the city imparting his knowledge to a team of seven Canadian child advocates brought in for two weeks of training.
Every 100 metres or so, middle-aged and older Western men shuffle down the pathway or lean against the ledge separating land from rocks and sea.
"Guys sitting there, staring around, waiting to make the right eye contact. I've been down here when your skin is crawling and you're ready to punch people," Mr. McConaghy said.
The city is the same location where Interpol alleges one of Canada's most infamous sexual predators, Christopher Neil, carried out his crimes against children.
Mr. Neil spent five years in a Thai prison after experts unscrambled computer images of him sexually abusing children.
While Canada has laws that can prosecute offenders who commit such crimes in other countries, Mr. Neil has never been charged at home. Neither the RCMP nor the Crown prosecutor's office returned a request for information on possible charges against him.
When Mr. Neil returned to Canada last year he was placed under a series of strict conditions to protect children.
They are conditions that he has already admitted to breaking. In October, he pleaded guilty in a Richmond, B.C., court to breaching his recognizance. The court heard Mr. Neil had in his possession a computer capable of connecting to the Internet.
He'll be back in the same courthouse Thursday for a pre-sentence report.
Only a handful of sex tourists, who exploit children in countries with underdeveloped legal systems and lack of child protections, have ever been prosecuted under the rarely used laws targeting Canadian pedophiles abroad.
Mr. McConaghy's rare blend of police forensics skills and Cambodia street savvy was instrumental in convicting Canada's first child sex tourist, a British Columbia man who trolled Phnom Penh for prepubescent girls.
After putting Donald Bakker behind bars in 2005, Mr. McConaghy couldn't bear leaving broken girls to fend for themselves and so he felt compelled to start the Vancouver-based Ratanak Foundation to help rehabilitate the former hotel clerk's victims.
Canadian authorities know citizens continue to visit foreign locales specifically to buy sex with children, but overseas investigations are complicated, time-consuming and costly.
Legislative reforms announced in September by Prime Minister Stephen Harper, however, could shore up Canada's powers to stop the cycle of depravity. The preventative laws would require convicted sex offenders to alert authorities before departing the country – in turn allowing Canada to warn border officials before they land.
Mr. McConaghy makes several visits to Cambodia each year, this time accompanying office staff and fundraising volunteers who have shown long-term dedication to protecting children from such Western predators.
His goal was to provide his companions a chance to peer directly into the "big brown eyes" of children still sold nightly in Phnom Penh's back-alley brothels, moving them beyond facts to understand the stomach-churning reality from their hearts.
"It's very powerful in Tuol Sleng [torture prison] to walk through the little holding cells, recognizing that later on, they will see rape cubicles that look very similar," Mr. McConaghy said of the former Khmer Rouge site, now open to tourists, used to extract false confessions from Cambodians during the Pol Pot-led genocide in the mid-1970s.
"There's a continuum here for abuse. For different reasons and different ways, but there's a continuum here. That is not history, that is happening today."