INDIANAPOLIS -- Police found $2.5 million worth of marijuana plants growing inside a pole barn on Indianapolis' southeast side on Thursday.

Investigators raided the structure Thursday morning, arresting the homeowner, John Coulter, 49, 6News' Jack Rinehart reported from the scene.

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Images: Police Bust Massive Indoor Marijuana Grow

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Police told Rinehart that it appeared the large pole barn on the 19-acre property had been built specifically for growing the plants, with geothermal heating, a special air circulation unit and a high-tech security system.

"It was an extremely well-designed pole barn. He was growing 200 plus plants," said Officer Rich Tyner. "It was designed for that specific reason. You can tell by looking at it that he built it pretty much from the ground up."

One veteran drug investigator told Rinehart that the operation was the largest and most professional indoor grow that he'd seen in his career.

Police also seized several weapons from the home, including shotguns and handguns.