Craig Kloppenberg spent three decades on SWAT teams devoted to arresting pot dealers and eradicating their growing operations.
But now, he and his partner, Joel Smith, also a former law enforcement official, help protect pot producers as compliance consultants for nearly a dozen marijuana operations in Colorado.
They are just two of the thousands of new job and business opportunities that accompanied the state's legalization of marijuana for medical and recreational use.
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Kloppenberg and Smith's services are vital, as owners who are found not in line with standards and procedures can face fines, or have their licenses suspended or even revoked.
"If you could make more money, give a better life to your family, why not?" Kloppenberg said. "I believe it's going to be very lucrative."
Army veteran Ted Daniels also saw an opportunity for a profitable business. His company, Blue Line Protection Group, provides trained security staff to escort growers and dispensary owners on their delivery and other runs—making their product, cash and clients safer.
Leo Pavlushkin, a former member of the Soviet military who went to sniper school in Russia, is vice president of operations at Blue Line.
"In the business we're in, there is a very high and volatile threat for us," said Pavlushkin, whose large stature and thick Russian accent make him hard to miss.
Criminals also see opportunities, with the resulting risk of more pot growing operations and shops being robbed and burglarized.
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Although U.S. Attorney General Eric Holder said the Obama administration would soon announce regulations letting banks handle the accounts of cannabis growers and sellers, it is so far illegal for banks to engage with such businesses—-making Blue Line an even more attractive asset.
But Daniels said there will be a need for his company even after banking services become available.
Federal and local governments have invested millions of dollars in training and educating public employees such as himself, Daniels said.
"If you took the amount of money that the government has used to train these guys to the level that they're at, you can't duplicate that in the civilian world. ... All the combat vets who are getting out that are highly trained—we have places for them," he said.
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Despite those who might disapprove of those who have switched from pot busters to pot protectors, Kloppenberg and Smith are confident that others will follow in their footsteps.
"I've got several law enforcement buddies waiting on Joel and me to expand the business ... and give them a call. ... They're ready to come right now."
—By CNBC's Dina Gusovsky. Follow her on Twitter @DinaGusovsky.