As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, NOTICED R1 WINDOW ELECTRICAL ARC FOLLOWED BY R FWD WINDOW CAUTION MSG FOLLOWED BY SPIDER WEB CRACKING IN R1 WINDOW. EMERGENCY DECLARED. AIR TURN BACK TO CVG. REMOVED AND REPLACED R1 WINDOW ITEM CONTROLLER IAW B767 AMM 30-41-01. OPS CK GOOD. AND REPLACED R1 WINDOW IAW AMM 56-11-01. OPS CK GOOD. AIRCRAFT RETURNED TO SERVICE.