A financial adviser with offices in Chesterfield and St. Charles was sentenced to 63 months in federal prison Thursday for bilking investors out of $3.9 million in a pyramid scheme.

Aaron W. Duncan, 33, of Defiance, while CEO and owner of the Duncan Group, promised more than 50 people that their money would be invested in real estate. He promised that their money was safe, secured by a deed on their investment property or some other type of security, prosecutors said.

Prosecutors said Duncan actually only bought about 10 properties, and lost money on those. He used most of the money to pay investors, support the business or pay his personal expenses, prosecutors said.

Duncan pleaded guilty of mail fraud and money laundering in April.

In court Thursday, Assistant U.S. Attorney John Bodenhausen said that Duncan devastated the lives of some of his victims. Bodenhausen spoke of on family that lost their entire life savings, a man from whom Duncan took money while the man's son was dying of cancer and a widow with five children who lost $500,000.

In addition to the prison time, U.S. District Judge Carol Jackson ordered Duncan to repay the money. Lately he has been working for a lawn care company, earning about $1,000 per month, court records show.