PHOENIX -- Authorities say a Canadian teen has threatened the life of Maricopa County Sheriff Joe Arpaio for the seventh time.
The 16-year-old boy from Alberta was arrested and remanded into custody Thursday after allegedly threatening the sheriff via email. He is scheduled to appear in court May 8.
The teen allegedly said he could not wait to stab Arpaio 50 times and slit his throat with a knife, then dispose of the body in a trash bin and set it on fire.
He also reportedly stated that he would be Arpaio's "worst nightmare," and was not worried about the "cowardly" authorities in Canada or being extradited to Maricopa County.
The sheriff's office said the teen was arrested several times in the last 10 months and is awaiting sentencing for the previous threats. He also spent 30 days in a mental health facility under a court order.
"He not only appears to be very mentally unstable but he constantly warns of his desire to commit violence," Arpaio said in a statement. "This suspect is a ticking time bomb. My patience is running thin. If I have to return to Canada again to testify, I will in order to aid in the prosecution of ths menace."
Arpaio says he is worried about his family and the citizens of Canada.
The teen reportedly made death threats against the sheriff's family last July and October.
He is not the first Canadian resident to threaten Arpaio's life.
Matthew Carl Sanderson, 37, was arrested by Toronto police after saying he would shoot Arpaio in the head or heart, poison him, blow up his car, or burn him alive.
The sheriff traveled to Canada in 2007 to testify in the case and Sanderson was found guilty.