KANSAS CITY, Mo. -- An appraiser who alerted the FBI to a possible mortgage scam involving former Jackson County Executive Katheryn Shields took the stand during her trial on Tuesday.

Shields, her husband and two others are on trial in connection with mortgage fraud.

Tuesday's first witness said he was called to appraise a property but became suspicious when he saw the sale price was double the price listed in a real estate database.

He told the court that he alerted the FBI and recorded a number of phone conversations about the transaction.