Some are mentally ill, others self-described pranksters.
But all are a serious threat, maintains Maricopa County Sheriff Joe Arpaio. Since he was first elected in 1992, the outspoken lawman has received hundreds of death threats, sheriff's officials said.
Currently, there are 11 threat cases under investigation and two trials pending. Five people already have been convicted of threatening Arpaio.
The cases include that of a 22-year-old man who plans to ask a judge on Wednesday to let him out of a plea agreement and the pending trial of two Mesa men accused of plotting to kill Arpaio and former Arizona Gov. Jane Hull.
"I don't like talking about this when it affects me," Arpaio said recently before speaking for 20 minutes on the subject.
"I'm the sheriff, but I'm also the victim," he said.
The 70-year-old sheriff said he gets the threats because he is outspoken and controversial and keeps a "high profile."
"Some people say I reach the celebrity stage," Arpaio said, adding that he refuses to cut back on public appearances or accept extra security.
If Arpaio truly is a celebrity, then it is no surprise that he was stalked by 39-year-old Gabriel A. Espinosa, who also stalked a local television news anchor and entertainers Madonna and Mariah Carey.
But court records show Espinosa, who is serving a 3 1/2-year sentence in the state mental hospital, just might not like the sheriff.
Two psychiatrists concluded Espinosa was legally insane when he stalked the news anchor but legally sane when he called in death threats to Arpaio in 2000 because he understood the wrongfulness of his actions.
But the doctors concluded that if Espinosa weren't mentally ill, he never would have threatened Arpaio.
Court records show mental illness may have been a factor in other cases — one in which 70-year-old Mesa resident Chester Wawrzyk admitted phoning the sheriff's office and vowing to kill Arpaio. Wawrzyk was being committed to a mental hospital at about the time he pleaded guilty, according to court records.
In another pending case, defense lawyer Jeffrey Roth wrote in a court document that Terry R. Jefferson's letters not only contain threats to Arpaio but also show his "bizarre and confused thought process."
Jefferson's competency is being evaluated at the Arizona State Hospital, court records show.
And then there is 79-year-old Donald Cochran, who was diagnosed with dementia in 1998, court records show.
The Mesa resident is charged with conspiracy to commit murder with two other men, and authorities claim in court documents that he wanted Arpaio killed in retaliation for losing jail privileges. Authorities also allege that he wanted to kidnap Hull to force her to sign a pardon, but that she would have to be killed and “buried under a tree.”
“A lot of nut cases kill people. We take nut cases serious, too. Probably more serious,” Arpaio said. Chief deputy David Hendershott, who is in charge of a unit of detectives that investigates threats against Arpaio and other public officials, said there are 11 investigations on the "threat board" involving the sheriff.
"They're kind of all over the board," Hendershott said. "Some very serious, some not so serious, but they are still pending."
He said, "The problem with dealing with threats, you're dealing with the unknown. It's sort of like terrorist acts."
Detectives have made frightening discoveries while investigating the threats.
Stephen Hancock, 36, sent Arpaio a vulgar letter using someone else's name, and detectives found in his Sun City home 22 weapons, high-capacity ammunition clips, books on assassinations and "terrorist" magazines.
Phoenix resident Anthony Chos, who threatened to stab Arpaio in the heart and cut his throat, was arrested with a folding knife in his pocket. According to court documents, both men said their threats were pranks.
Arpaio said most of the threats in his 40-year law enforcement career didn't come until he was elected sheriff.
He senses his wife is more concerned for his safety than ever, but that she is a "trouper."
Other local law enforcement agencies aren't so willing to speak about threats against their top officials.
A spokesman for the U.S. Attorney's Office declined comment. Bill FitzGerald, a spokesman for Maricopa County Attorney Richard Romley, issued a single statement and would answer no questions.
"Not just Rick, but members of our staff do get death threats, and we take them all seriously. But we really don't talk about them beyond that," FitzGerald said.
Defense lawyer Ulises Ferragut, who represented Chos and is defending two other men accused of threatening Arpaio, said he believes the threats should be taken seriously, but that Arpaio's investigators go too far in trying to prove their cases.
Ferragut is representing James B. Saville, 22, who is trying to get out of a plea deal after sheriff's detective Wayne Scoville came forward and said Saville was set up when he made a bomb intended for Arpaio.
Ferragut also is defending James Cozzolino, a Peoria man who has been under investigation but never charged since 1998, suspected of getting on the sheriff's office radio frequency and threatening Arpaio.
Cozzolino, who has received a court order to stay away from Arpaio, goes to trial March 3 in connection with an unrelated shooting incident.
Cozzolino said a plea agreement in the shooting case stipulated that he plead guilty to charges stemming from the alleged threats, but he refused.
"It would have been a lie," Cozzolino said.