The world's elderly are on a crime spree

In May, nine men allegedly stole more than $300 million in cash and gems from the Hatton Garden in the heart of London's jewelry exchange. The heist is considered one of the most brazen in recent memory.

The thieves had to disable the elevator, climb down the shaft, and then use heavy duty power tools to drill into the vault before making off with the loot - undetected.

This was clearly the work of some seasoned professionals.

But when cops finally rounded up the alleged culprits earlier this month, they found the crew even more seasoned than they could have imagined.

The youngest was 43-years and the oldest 76, while the rest ranged between 48 and 74, with two of them pushing 60, according to London Metropolitan Police.

As unbelievable as it seems, the Hatton Garden Heist is part of a growing disregard for the law among the oldest members of our society.

BloombergBusiness recently reported a sharp uptick in crime rates among senior citizens around the world. In South Korea for example, crimes committed by people 65 and over rose 12.2 percent from 2011 to 2013, which includes a shocking 40 percent increase in violent crime, such as murder, robbery, and rape, according to the Korea Times.

Geriatric crime in Japan has also risen, almost doubling since 2003, The Telegraph reported. The elderly now account for more shoplifting offenses than teenagers there.

In the Netherlands, a 2010 study revealed a similar spike in arrest rates and incarceration among the elderly. And in London, arrests of the elderly have risen 10 percent since 2009. The number of senior citizens in prison has also risen at a rate three times that of the overall prison population over the last decade, according to Bloomberg.

The US, however, may be bucking the trend. The rate of elderly crime among seniors has decreased since the 1980s, according to Bloomberg. While the elderly prison population has grown by 550% over the last 25 years, it may be attributable to longer prison sentences for drug -related crimes, as The New York Times notes.

But according to data portal IndexMundi, the United States also can't claim as large a senior population as Japan (25% over the age of 65), the United Kingdom (18% over the age of 65), or the Netherlands (18% over the age of 65). The senior demographic that currently comprises 14% of the US population, however, is set to rise in the coming years as people live longer.

So why are we experiencing this grey crime wave, and what can we do to stop it?

Factors such as inadequate retirement savings and the increased costs of medical care and food can attract a senior citizen to crime, Robert Laura, a financial planner specializing in retirement, wrote for Forbes. Emotions, like loneliness, isolation, depression, stress, anxiety, inadequacy, and boredom, might play a role, as well.

South Korea blames the spike in senior crime on higher poverty rates among the elderly. Bloomberg notes that percent of senior citizens live below the poverty line in South Korea.

The Netherlands concluded in its report that the spike in elderly crime can be attributed to "psychiatric, psychological, financial-economic, judicial, and psycho-social factors."???

Bas van Alphen, a psychology professor studying criminal behavior at the Free University of Brussels, theorized that elderly people in developed nations tend to be "more assertive, less submissive, and more focused on individual social and economic needs," he told Bloomberg. "When they see in their peer group that someone has much more money than they do, they are eager to get that."

All this news comes with a warning.

As people continue to live longer, there will be a growing senior population susceptible to crime. Laura advocates that along with smart financial planning, retirees need to have a social network to support them in their later years, plans to stay physically and mentally fit, and healthy ways to channel their boredom.