Federal securities regulators allege that three Minnesota men who died in a February murder-suicide defrauded dozens of investors in small communities, notably Belle Plaine and Pierz.

In a civil suit filed Thursday, the U.S. Securities and Exchange Commission claimed that Spartan Trading — an unregistered investment fund — had raised over $3.7 million from 2019 to 2023, purportedly for day trading in stocks.

Spartan was founded by Richard Myre, Dale Dahmen and Dominick Dahmen. Myre, 44, shot and killed Dale Dahmen, 55, and his son Dominick, 25, in Bloomington, before turning the gun on himself.

Spartan Trading "was a sham that defrauded investors in multiple ways," the SEC said in a filing in U.S. District Court for Minnesota. Myre, who controlled Spartan's bank account, and the Dahmens, raised money to invest in stocks. They then failed to make those investments, the filing said.

Instead, the funds sat idle in Spartan's accounts and "were slowly eaten away as Myre withdrew money for himself, the Dahmens and investors in an attempt to keep the scheme going."

Myre, of Belle Plaine, received over $1.1 million from the Spartan fund, while Dale Dahmen received about $649,000 and Dominick Dahmen received $173,113, the SEC alleges. The Dahmens were from Buffalo, Minn.

The SEC claims Spartan and Myre violated U.S. securities laws, and that the Dahmens received "unjust enrichment" from the alleged fraud.

Myre provided investors with falsified accounting documents, saying Spartan's fund was earning consistently positive returns, the filing said. "In some cases, investors put additional money into Spartan after receiving phony statements."

The fallout for some investors was severe.

"At least one couple who had invested over $100,000 with Spartan had to sell their home and move out of state to be closer to family," the filing said. "Other investors have lost retirement savings and inheritances."

Spartan's fraud began to "unravel" in late 2022, and Myre and the Dahmens began meeting about the fund's trading activity and structure, the SEC claims.

On the afternoon of Feb. 1, Myre arrived in a pickup truck in the parking lot of the France Place business center, near where France Avenue crosses Interstate 494. About eight minutes later, the Dahmens arrived in a minivan. The father and son got into Myre's pickup.

There was a "commotion" in the vehicle, and Myre pulled out a handgun and shot the elder Dahmen twice, killing him, according to Bloomington police. A struggle ensued between Myre and the younger Dahmen, before Myre shot him seven times. He then killed himself.

After news of the deaths, investors began asking Bloomington police and the SEC about the status of their investments in Spartan Trading.

The SEC's lawsuit names Spartan and Myre's estate as defendants. The Dahmens are named as "relief defendants," meaning they allegedly benefited from an illegal scheme but are not accused of breaking laws.

The SEC seeks to determine what can be recovered for allegedly defrauded investors. A review of Spartan Trading's records shows less than $6,000 remaining in a Bank of America account and about $400 in a TD Ameritrade account, the SEC said.