DENVER -- An Arvada woman was sentenced to 20 years in prison for defrauding over three dozen firefighters and police officers by posing as a CPA and tax attorney, prosecutors said Wednesday.

Denise Ruth Smith pleaded guilty on Jan. 30 to three counts of aiding in filing a fraudulent or false tax return, each a class five felony; and three counts of criminal impersonation, each is a class six felony, said Pam Russell of the First Judicial District Attorney's Office.

Working out of her home in Arvada, Smith presented herself as a CPA or a tax attorney to prospective clients but would inflate deductions or create deductions for her clients which resulted in a reduced taxable income, lowered tax burden and increased the amount of their refund, Russell said.

Many of these victims were audited and were required to pay penalties and interest.

Smith was serving a 10-year probation sentence in Jefferson County when she committed the offenses in this case. She was convicted in 2001 for the same charges, fraudulently presenting herself as a CPA or tax attorney and defrauding clients.

Smith has a string of fraud cases dating back to 1988. Her first felony conviction was in 1997 in Arapahoe County when she pleaded guilty to theft and was sentenced to eight years probation. She violated the conditions of probation but was given another chance and resentenced to eight years probation.