The complaint alleges that between 2001 and 2007, 48-year-old Frederick J Barton misappropriated clients' money for his own personal use.
Among the victims of the scam was a 90-year-old Alzheimer's patient who saw her assets fall from $1.3 million in 1999 to under $100 by 2004. The newspaper said Mr Barton is accused of diverting funds from the late woman's accounts once he learned of her condition.
He is also accused of fraudulently selling over $1 million worth of shares in his investment company, a firm he set up after being dismissed as a manager at AG Edwards & Sons, the site noted.
Federal prosecutors contest that Mr Barton used at least half of these funds to pay off personal debts and cover other expenses.
The Securities and Exchange Commission had previously filed civil charges against Mr Barton in June.