TSA changed the guidelines on Duty Free purchases. Now, when clearing TSA on a domestic connection from an international flight you can bring your duty free purchase through security. Over the last few years I have had no trouble taking duty free bags through security in SFO when connecting from international flights. Here is the information on the TSA website:
https://www.tsa.gov/travel/security-...g/liquids-ruleInbound International Flights
You may carry duty free liquids in secure, tamper–evident bags, more than 3.4 oz or 100 ml in your carry-on bag if:
- The duty free liquids were purchased internationally and you are traveling to the United States with a connecting flight.
- The liquids are packed in a transparent, secure, tamper-evident bag by the retailer and do not show signs of tampering when presented to TSA for screening.
- The original receipt for the liquids is present and the purchase was made within 48 hours.
Liquids more than 3.4 oz or 100 ml not in a secure, tamper-evident bag must be packed in checked baggage.