ABOVE: Winnebago Mayor Scott Robertson and his son, Jacob Jon Robertson. Submitted photo.

WINNEBAGO — Winnebago Mayor Scott James Robertson, 67, and his son Jacob Jon Robertson, 46, were arrested Thursday following a drug raid at three Winnebago properties.

Two counts of felony first-degree unlawfully cultivating 23 cannabis plants, felony first-degree aiding and abetting unlawfully cultivating more than 23 cannabis plants and felony first-degree unlawfully cultivating more than 23 cannabis plants were filed Friday against the Robertsons in Faribault County District Court.

About 240 plants believed to be marijuana and many other items of evidence were seized at 15/17 Main Street, 522 1st Ave. S.W. and 18195 340th Avenue, according to a South Central Drug Investigative Unit news release.

An investigation by the SCDIU, Faribault County Sheriff’s Office, Faribault County Attorney’s Office and other law enforcement agencies began in early 2023, according to the news release.

According to court documents, South Central Drug Investigative Unit Agent Briar Bonin received an anonymous tip in January 2023 indicating the owners and occupants of commercial grade greenhouses in Winnebago were cultivating a large number of cannabis plant.

Agent Bonin contacted the Minnesota Department of Agriculture (MDA) and learned that the property owners/operators including the Robertsons previously operated a licensed and regulated hemp cultivating operation through the MDA but did not register a 2023 hemp crop.

Agent Bonin requested the MDA perform a site inspection and test any growing plants in 2023. MDA advised that inspections require advance notice to the licensed party. Agent Bonin learned from witness information, that the Robertsons backed an enclosed trailer onto the property and used it to remove growing plants from inside greenhouses at the property.

In February 2023, the MDA inspected the property but found no crop growing in it.

This January, Agent Bonin was notified by anonymous tip that the Robertsons were cultivating a large number of cannabis plants in the greenhouses at the same property. Agent Bonin learned that Scott Robertson also owned commercial properties on 15/17 S. Main Street in Winnebago.

Agent Bonin received a January report from Faribault Chief Deputy Scott Adams that while visiting a business adjacent to 15/17 Main Street, he smelled a strong, unburnt marijuana odor that appeared to be coming from 15/17 S. Main St.

Contacting MDA, Agent Bonin discovered that Scott Robertson’s hemp license expired in December 2023 and had not been renewed and that the Robertsons had not registered a hemp crop since 2021.

Aware that indoor cannabis cultivation requires high power usage during growing periods for equipment such as grow lights, Agent Bonin issued a subpoena to BENCO Electric to review electrical usage records for Scott Robertson’s properties on Main St. and at 340th Avenue. Electrical use records showed patterns suggestive of active cultivation of a large number of plants through January.

On Feb. 7, 2024, Agent Bonin noticed a strong smell of unburnt marijuana in the area of 15/17 South Main St. The building had obscured windows and did not appear to let light in or out of the building.

Agent Bonin applied for and was granted a warrant to search for cannabis plants at both properties. Assisted by other task force agents and Faribault County Sheriff’s Office deputies, Agent Bonin executed warrants at both locations.

At the 15/17 S. Main St. building, 55 plants consistent in appearance with cannabis plants were found and producing flowers. The plants field tested positive for marijuana, with a THC concentration greater than .3. None of the plants matched known and registered hemp seeds/plants permitted to be grown in Minnesota. Registered hemp seeds and plants must have a THC concentration of less than .3%.

Executing a warrant at the 340th Avenue address, Agent Bonin discovered 185 plants growing in industrial greenhouses and a five-gallon bucket of apparent seeds.

Agent Bonin found a notebook at the greenhouse with detailed descriptions of rows and strains in the greenhouses that matched most of the plants in it. The notebook appeared to contain financial transaction information with dates as recent as Jan. 8, 2024 and indicated partner profit splits with shares of $120,000 for a total profit distribution of $360,000.

A separate search warrant obtained for 522 1st Ave. S.W. in Winnebago showed documentation from a company known as “elev.8,” a cannabis seed supplier. Documentation included seed pamphlets with seed prices and THC content. Many of the seed strains and plant names in pamphlets matched plant labels found in the 15/17 S. Main St. building. Most of the strains in the pamphlet had a listed THC content, all between 29 percent to 32 percent.

The Robertsons were taken into custody.

Jacob Jon Robertson retained Mankato attorney Patrick J. Casey Friday. An omnibus hearing was set for 1 p.m. March 25.

An initial appearance for Scott James Robertson was set for 8:30 a.m. Feb. 16.

The Robertson’s unconditional bail was set at $20,000, no bail with conditions Friday.

Scott Robertson was in his second year of a two-year mayoral term, according to the Winnebago City Clerk Office.