The woman set aside her purse one day while visiting her grown granddaughter in Forest Lake. That’s all it took for the young woman to pinch her 73-year-old grandmother’s checkbook and fund what prosecutors proved in court to be a $150,000-plus bilking of her bank accounts.

Washington County jurors on Thursday convicted Elaina L. Casello, 24, of multiple counts of identity theft and felony theft in a nearly two-year scheme that allowed Casello to pay household bills and a student loan.

“Financial exploitation of the elderly is an increasingly common occurrence,” said County Attorney Pete Orput, who described the victim as a “vulnerable adult.”

“This office has earmarked this offense for special attention,” Orput continued. “This conviction, we hope, should shout out a warning to those that would exploit the elderly that they will be held accountable.”

Casello posted bond and remains free until sentencing, scheduled for May 21. In an interview Friday, Casello said the case is nothing more than “a family dispute that got blown out of proportion.”

While awaiting sentencing, Casello said, she’s caring for her two children, going to college and tending bar. She added that she has not ruled out appealing the verdict.

Asked whether the county attorney accurately described her grandmother as vulnerable, Casello stifled a laugh and responded, “No.” Assistant County Attorney Fred Fink later said the county attorney’s office erred and should not have described the victim as vulnerable.

From February 2011 to late December 2012, according to the charges, Casello accessed her grandmother’s money three ways: writing checks to herself on her grandmother’s account and forging the signature, using the ill-gotten checks to pay bills and illegally accessing a bank account to pay bills electronically.

Prosecutors said that Casello, a onetime bartender in White Bear Lake, told a police officer that during one of her grandmother’s visits she stole the woman’s checkbook out of her purse.

Until this case, Casello’s troubles with the law had been limited to various driving infractions, including a drunken driving conviction.