As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURN TO FIELD. FLIGHT ATTENTDANT REPORTED A STRANGE ODOR IN CABIN. IT WAS STRONGER TOWARD THE REAR OF THE ACFT. REMOVED & REPLACED THE AIR RECIRCULATION FILTER IAW AMM 21-21-41. R & R THE 100HM AND 101HM OZONE FILTERS. ACFT OK FOR SERVICE.