01/22/2014 11:17 EST | Updated 03/24/2014 05:59 EDT

Jeffrey Boucher mystery: How to disappear without a trace

The mysterious disappearance of 52-year-old high school teacher Jeffrey Boucher took another turn this week when police announced they were calling off the search for the Whitby, Ont., man, with one detective commenting that "Mr. Boucher quite simply appears to have vanished.”

It raises the question: How does someone just disappear without a trace?

Private investigator Mark Mendelson, a former Toronto police homicide detective, said he has encountered cases of people mysteriously disappearing.

“Most of those cases do not end in a positive way,” Mendelson told CBC Radio’s Metro Morning on Wednesday.

Mendelson theorizes that Boucher’s case will turn out in one of three ways: First, that the married father of two had a medical issue while jogging and his body was missed in the search, or second, that he took his own life and took steps beforehand to ensure he wouldn’t be found.

The third scenario, which Mendelson said is the most unlikely, is that Boucher is alive and well somewhere and has “gone to great efforts to completely vaporize off the face of the earth.”

Without a trace

Mendelson said that staging your own disappearance is easier than you would think and that people have been doing it for decades. In one infamous case, a British soldier named Philip Sessarego faked his own death in 1993, before resurfacing almost a decade later, publishing a book under his new identity, Tom Carew.

“They’re motivated. They’ve made plans in advance in terms of squirrelling away cash, things of that nature, so they don't have to deal with ATMs, banks or whatever,” Mendelson said.

Once someone is ready to disappear, all they need is a piece of fake ID, which Mendelson said you can easily find online.

“All you need is one piece of identification — albeit fraudulent, but it looks legitimate — that gets you in the door to sort of build a new identity. From there, you can go and get another piece of ID, set up a bank account,” Mendelson said.

He said there have been cases of criminals who disappear for decades, living under the radar, only to be discovered living comfortably in another state or country.  

But in the case of Boucher, Mendelson warns people not to jump to any conclusions and brings up another high-profile case — Mariam Makhniashvili, a Toronto teenager who went missing in 2009. In the months following her disappearance, people reported spotting her in different cities across North America.

“She was in Calgary, she was in the United States, she was everywhere,” said Mendelson. “But in actual fact, she was underneath the bridge at the Don Valley golf course.”

Police believe she took her own life.