A Stillwater financial adviser has been sentenced to more than six years in prison for stealing money from his clients in a scam that spanned five years.

Levi D. Lindemann, 40, pleaded guilty in federal court in March to mail fraud and money laundering. On Tuesday, U.S. District Judge Donovan Frank sentenced him to 74 months in prison.

Lindemann’s company, which operated as Alternative Wealth Solutions, solicited more than $4.3 million from about 50 investors in Minnesota and Wisconsin between 2009 and 2014. Most of his clients were unsophisticated relatives and friends, according to court documents, and many gave him their entire retirement savings.

Lindemann skimmed at least $1.9 million for himself, court documents show, using it for personal expenses including an Infiniti QX56 SUV for which he paid nearly $60,000. Some of the money went to cover the returns he promised to other investors.

Lindemann hoodwinked his clients by creating fake secured notes to serve as proof of their investments. They thought their money was secured by real estate and life insurance policies on the secondary market.

“Lindemann abused his position of trust as a financial adviser to steal from his clients, including the elderly,” said state Commerce Commissioner Mike Rothman in a news release Wednesday.

From 2000 to 2012 Lindemann was a registered representative associated with various broker-dealers, a Commerce spokesman said. The Securities and Exchange Commission permanently barred Lindemann from selling securities or providing investment advice, he said.

The government sought a longer sentence for Lindemann of 108 months noting the devastating impact the swindle has had on his victims.

One investor, a highway maintenance supervisor in his 70s, said he can’t retire now because he turned over his entire life savings to Lindemann.

“Levi has [caused] us lots of stress and sleepless nights,” the man said in court documents. “He ruined our elderly lives as we don’t have any finances to live on and still have to work.”