WASHINGTON—Three senators, including Sen. Amy Klobuchar (D-Minn.) who chairs the Senate Judiciary Committee’s antitrust panel, wrote a letter to Amazon.com Inc to express concern about its palm print recognition system, Klobuchar’s office said Friday. Amazon began rolling out biometric technology at its Whole Foods stores around Seattle in April, letting shoppers pay for items with a scan of their palm. The system, called Amazon One, lets customers link a credit card to their palm print. Klobuchar, who was joined by Sen. Bill Cassidy (R-La.) and Sen. Jon Ossoff (D-Ga.), expressed concern in the letter dated Thursday about both privacy and competition related to Amazon One. “Our concerns about user privacy are heightened by evidence that Amazon shared voice data with third-party contractors and allegations that Amazon has violated biometric privacy laws,” the lawmakers wrote in the letter. “We are also concerned that Amazon may use data from Amazon One, including …