TAMPA — Senior Master Sgt. Shannon Shuck walks through the apartment complex in a bulletproof vest, a gun holstered on his belt.

He has a radio, a badge and a mission at the moment. Some residents are causing trouble by inviting gang members to their apartment. So the officer strides through the steady rain and approaches a woman sitting outside.

Shuck is not law enforcement, though with his weapon and uniform that's not always obvious. He is a private security officer with Critical Intervention Services, a Largo-based company that operates in Pinellas, Hillsborough and Pasco counties.

In Florida, there are 27,910 people like him — licensed armed security officers.

They patrol dangerous areas as hired security. In many ways, they function like cops, but without crossing legal barriers.

Last month, one of the company's Hillsborough officers died in a fatal shooting. Michael Valentin, 38, had just started in October. It was the second death in less than two years for a company that had escaped the worst for nearly 20 years.

To CIS Capt. Shaun Fogarty, who has worked with the company for almost seven years, the shooting was a sobering reminder of what officers like him face every night.

"We work in inherently dangerous areas," he said.

• • •

Valentin was shot, authorities say, by a 16-year-old who wanted the officer's gun.

In May 2011, officer Mathew Little was ambushed by a 20-year-old who made it known he did not like law enforcement or private security, St. Petersburg Police say.

CIS founder and director KC Poulin spoke with Valentin's widow. Fellow officers attended his funeral.

But Poulin does not think any procedural changes could have prevented the deaths. He does not plan to make any changes.

"They're armed. They're trained. They wear bulletproof vests," he said. "You can't manage all risks."

CIS is often hired by apartment complex owners looking to improve their property. The security company's job is to gain control, then maintain it. They call it "anchoring." The company charges up to $30 an hour and requires the complex to use them every night.

CIS's strategy: Befriend area kids first, then their parents. Talk to residents. Get them to be the eyes and ears. Trouble-makers get eviction notices.

While local cops get hundreds of hours of training, CIS's officers still do more than the state-mandated 68 hours.

CIS officers are trained both in the classroom and in the field. They are tested on a protocol handbook more than an inch thick. Each year, officers get money to attend security training classes, Poulin says.

Because the CIS officers' focus is on proactive community-building, they know, for example, who lives in Building 2. They play basketball with kids on the complex's court. Poulin says they try to intercept children in tough situations and help them.

"But there is such a thing as evil," he said.

• • •

It's 7 p.m., dark and rainy as Capt. Fogarty drives through the University Community Area and Temple Terrace in his marked silver car, a Ford Interceptor.

Dispatch calls go through his radio. Incidents pop up on a laptop mounted to his dashboard.

He wears a crisp, black uniform with a badge and name plate. The foot officers in the area wear "battle dress uniforms."

"It looks aggressive," Fogarty says. "It acts as a deterrent, projects power and authority."

The company made national news in the early 1990s when Poulin started putting officers in the University Community Area. Such intense security was a new idea, and it was lauded as a way to reduce neighborhood crime. Other companies followed.

CIS writes detailed reports on each incident. They pass tips to law enforcement. The security officers have the power to enforce lease agreements and can help get tenants evicted.

They are even allowed to detain suspects in the case of "forcible felonies," such as a robbery. CIS security officers carry guns, batons and handcuffs.

Over the past year, they responded to 749 violent acts and were involved in 737 incidents that ended with arrests, CIS reports. They recorded 1,270 trespassing incidents and fielded 12,404 calls to their dispatch center.

Local law enforcement say they have good relationships with CIS. The officers are like extra-helpful citizens, passing along information and keeping an eye out for people with outstanding warrants, several agencies said.

CIS officers like to think of themselves as the people who "fill the gap" in the law enforcement world. They have more time to be proactive. Sometimes they are the first to the scene.

After Valentin was shot to death on Nov. 21 at the Grande Oaks Apartments in East Tampa, CIS hosted a community event at the complex.

The company brought games, a football, tug-of-war and water balloons. They offered hot dogs and lemonade.

"We want the community to know we're not going anywhere" Poulin said.

Jessica Vander Velde can be reached at jvandervelde@tampabay.com or (813) 226-3433.