Terrance W. Gainer, former Senate sergeant-at-arms and Capitol Police chief, is heading security operations for a medical-marijuana facility that has applied for a license in Hagerstown, Md. (Katherine Frey/The Washington Post)

For much of his 46-year career in law enforcement, Terrance W. Gainer viewed marijuana as a substance to be confiscated and its sellers as criminals to be investigated and arrested.

He is now security chief for one of the nation’s leading medical-marijuana growers, tasked with, among other things, protecting a 20-acre site in Western Maryland that could become home to one of the state’s first cannabis-growing operations.

The new job, the former officer says, has required something of an attitude adjustment.

“You have to suspend your disbelief of what you’ve learned in the past,” said Gainer, a Vietnam War veteran who retired last year as the U.S. Senate’s sergeant-at-arms and before that held senior jobs in federal, state and local police agencies.

“This wasn’t something I thought I’d be doing late in my career,” said Gainer, 68. “But I did my homework on medical marijuana, and I said, ‘If elected officials decided to legalize these [operations], then I know how to secure them.’ ”

A marijuana cultivation facility in Denver. (David Zalubowski/AP)

Maryland passed a law in 2013 allowing medical cannabis, but a dispute over which entities could grow and sell it delayed the launch of any operations until 2016. Regulations allow for 94 dispensaries, two per state Senate district, and 15 facilities to grow cannabis plants.

Regulators have received nearly 900 applications from prospective growers, processors and sellers of medical marijuana — including 102 requests to grow marijuana. There were many duplicate applications from would-be shop owners eager for permission to operate a store in one of the state’s 47 senatorial districts, officials said. The commission is reviewing the applications and expected to start issuing licenses at some point in 2016.

Police-to-pot protector

Gainer, who lives in Annapolis, was born in Illinois and spent much of his policing career there before coming to Washington in 1998 as a top aide to then-Police Chief Charles H. Ramsey. He left the department after four years to become the U.S. Capitol Police chief, and four years later, he began an eight-year stint as the Senate’s sergeant-at-arms.

After leaving the Senate, he wanted to keep working, so he launched a security-consulting business. Meanwhile, across the country, law enforcement authorities were talking about how to deal with new laws legalizing the use of marijuana, either for medical or recreational purposes. Gainer heard about the issue from some of his old colleagues and associates, including Robert White, a former D.C. deputy chief who had become police chief in Denver, where recreational pot is legal.

Eventually, Gainer received a call from Mike McClain, an old college friend and former Illinois state legislator. McClain had helped a marijuana-growing company, Green Thumb Industries, launch in Chicago, and he suggested that Gainer work with it to develop security measures.

“It became pretty clear to me that sophisticated people were involved with GTI and that they had a medical community behind them,” Gainer said. “So as I was building my practice, I felt comfortable with the idea of working with them.”

The move from onetime drug-law enforcer to pot protector, he said, meant some good-natured ribbing from other cops and former cops.

“Police in general can have some gallows humor, and some of that was going on,” Gainer said. “Legalized marijuana is very new, and most of my contemporaries grew up in an era when marijuana was the boogeyman. But people’s positions have morphed over time, and no one has shunned me.”

Because Gainer also does security consulting for the Justice Department, he did have some concerns about reactions from the federal government — which still considers marijuana an illegal controlled substance.

“I was worried about whether they would look askance at it,” he said. “But the reaction from several people I’ve heard from is that they’re happy to have a professional at the security end of it.”

Gainer said he has never used marijuana and doesn’t have a prescription for it. But he is comfortable with the concept.

“I think medical cannabis has some wonderful benefits,” he said. “And I’ve talked to family members where it has made a difference in their lives.”

Job opportunities

GTI has applied for a license to build an indoor cultivation facility and grow marijuana on the site it purchased in Hagerstown — an economically depressed former railroad and riverboat hub in Washington County, about 70 miles northwest of the nation’s capital.

The county’s all-Republican Board of Commissioners expressed strong support for the plan.

GTI says it could build the 75,000-square-foot facility on the city’s rural outskirts and begin growing within six months of being awarded a license. The company would be able to start shipments within 10 months of approval. Gainer’s job is to ensure that the building and its contents don’t become an attractive target for criminals. He also has to set the minds of elected officials and residents at ease.

Maryland requires growers to comply with local ordinances and follow strict guidelines for security and product safekeeping, tracking and quality control. In the license application, the state asks prospective growers to answer 50 questions about security issues ranging from lighting and surveillance to employee training and collaboration with local law enforcement.

Gainer said it is all familiar territory, noting that his job with the Capitol Police in the post-9/11 era included protecting some of the biggest and most politically sensitive targets anywhere.

GTI says it plans to employ 30 to 50 people during its first year and hopes to eventually expand its workforce to about 200. That is welcome news in a town where the 5.1 percent unemployment rate is the same as the state overall, but the poverty rate hovers at around 25 percent, compared with about 10 percent statewide.

“A lot of people see the job numbers associated with it, and I think they’re excited about that aspect,” said James Jenkins, spokesman for the county government, who described the reaction at public hearings as almost entirely positive.

Tracie Hovey, who owns a public relations and advertising business, said she welcomes the prospect of new employment and appreciates “what medical marijuana does for people who are ill.”

Security at the Hagerstown site would include eight-foot fencing around the building; motion sensors; cameras for daytime and nighttime surveillance; and 24-hour security personnel both on- and off-site to guard the complex and monitor video feeds. Employees would have to use key fobs or personal identification numbers to enter the building.

“Right now, this is a very safe and peaceful area,” Gainer said. “I have no doubt in my mind that once this facility is built that it will be equally safe and peaceful.”

Fenit Nirappil contributed to this report.