DETROIT — When Detroit filed for bankruptcy in 2013 and made major budget cuts, it set off a wave of police officers leaving the force to find better-paying opportunities in other cities. The resulting police shortage and ongoing retention problem has brought another wave — of private security companies.

It's become a booming industry here in recent years, with the largest contractor, Securitas, reporting 25% year-over-year growth since the city's bankruptcy.

Another successful player in the business is Threat Management Center, run by ex-Army paratrooper Dale Brown. His 60-person VIPER force serves a client roster of over 5,000 private citizens and 100 businesses. Altogether, he said, the company brings in about $2 million a year.

"Our goal is to create conditions where violence does not occur," said Brown, who began teaching his own brand of self-defense in the early 1990s. "We deter violent criminal behavior by projecting strength. So our vehicles have all white strobe lights. Our vehicles are black and chrome."

But how do the local police feel about it? Asked about the rise of private security in the city, Police Chief James Craig said, "Do we think that security guards who are visible in neighborhoods deter crime? Yes. Can security guards replace police officers? No."