The Philadelphia bound flight took off from Los Angeles was diverted on Thursday.
The passenger who made alarming statement was deborded from the American Airlines Flight 754 at Phoenix Sky Harbor International airport and was sent to a psychiatric clinic for monitoring.
"We had a situation where right after take off a passenger stood and walked to the first class section, where he stood at attention there and refused to take his seat," Sergeant Vince Lewis of the Phoenix Police Department.
"He began making statements that, although they were alarming and threatening in nature, gave the flight crew the indication (of possible mental health issues)," he said.
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