Date: 201905
Local time of day: 1801-2400
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: B767 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb; Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: Enroute
Human factors: Time Pressure; Workload
Second reporter function: First Officer
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Security; Deviation / Discrepancy - Procedural Weight And Balance; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
Detector: Person Flight Attendant; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Returned To Departure Airport; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Landed in Emergency Condition
Contributing factors: Environment - Non Weather Related; Human Factors
Primary problem: Environment - Non Weather Related

Narrative: Aircraft X first requested to hold at ZZZZZ while going through a checklist. Later; he came back to request to return to [departure airport]. He then [advised ATC] and [requested] vectors for a return to [departure airport]. I informed the [Controller in Charge] and at the time did not have a d-side. The pilot stated that his [situation] was a passenger disturbance; something I've never encountered when dealing with pilot [urgent situations]. The pilot began to sound a little agitated; so I immediately turned him to a heading of 360 and descended him to FL240. I was given a d-side whom I had to tell to call the next sector immediately. The pilot informed me that he would need to dump fuel. The sector requested him on a heading of 300 but with the fuel dumping update; they requested him on a heading of 360. I was instructed ask what level threat and the pilot stated a level 3. I was instructed to ask if the cockpit was secure and what the details of the threat were. The pilot stated that the cockpit was secure and that a passenger had threatened another passenger and the integrity of the aircraft. I was informed that because of the severity of the threat that he would need to be cleared directly to the [departure] airport and I did as instructed by the [Controller in Charge]. For some reason; the d-side did not coordinate this with the sector but his trainer walked across the aisle to quickly inform them and the [next] sector as well as informing them that the aircraft had begun its fuel dumping. More experienced d-side should be assigned when able during [urgent situations].


Second narrative: We experienced a security issue during the climbout. Purser called and informed us that passenger made a statement to [another] passenger that 'we all would be dead in 20 minutes.' Captain contacted Dispatch and informed them of our situation. The flying pilot leveled off at FL270. We decided as a crew to return to ZZZ. We performed the fuel jettison checklist and dumped 22;400 pounds of fuel. Once we completed the Fuel Jettison Checklist; we ran all appropriate checklist and performed an overweight landing on [Runway] XXC at 335;000 pounds. Nice smooth touchdown at 200 FPM.


Synopsis: ATC and B767 pilots reported a security threat from a passenger that prompted an air return.