A 43-year-old Auburn man was arrested on investigation of harassment after leaving a voicemail Tuesday morning threatening to kill Seattle Mayor Jenny Durkan, according to Seattle police.

Police traced the call to Durkan’s office from an Auburn home and arrested the man there.

The man, who police said gave his name and telephone number on the voicemail, was staying with a brother, who told police that the man’s mental health had been deteriorating in recent weeks. He has been diagnosed with illnesses including schizoaffective disorder and bipolar disorder and has been arrested more than 70 times, resulting in felony convictions for crimes including harassment, attempted robbery and custodial assault, according to police.

At an initial court appearance Wednesday, a judge found probable cause to hold the man on investigation of felony harassment. The Seattle Times is not naming the man because he has not been charged with a crime.

“The Seattle Police Department will fully investigate any threat made against any public official and will work with prosecutors to ensure they are held responsible,” the department said in a statement. “SPD detectives have previously investigated several other unrelated threats against City Council members.”

When asked about the voicemail during a news briefing Wednesday, Durkan called the incident “really unfortunate” and noted she and her family had been the target of a number of threats in the past.

“It just shows we are in a very difficult, troubled time right now, and this is yet another thing that many officials face,” she said.

A Seattle firefighter was arrested in February and accused of emailing threats to City Councilmember Kshama Sawant. Prosecutors said he posed as a colleague to send the threats after a “history of negative interactions” with that colleague.