SAN DIEGO — Police say they took unregistered shotguns from a man in Rancho Peñasquitos who made “bizarre and threatening social media posts” about a coronavirus conspiracy, threatening to “take things into his own hands.”

The man told police he believed COVID-19 was an “elaborate hoax to allow the tracking of Americans” through 5G cell towers, and warned family and friends that he was arming himself during the pandemic, according to a news release by the San Diego City Attorney’s Office.

“Multiple calls were made to the San Diego Police Department regarding the respondent’s conduct,” the city said, including about a trip to buy ammunition, where the 52-year-old was denied because of a prior criminal conviction. When he wasn’t allowed to buy the ammo, the man “reportedly was enraged by what he believed was a ‘government plan’ orchestrated by people who were targeting him,” the city attorney’s office said.

At that point, investigators say the man said, “I guess I’m going to have to take things into my own hands.”

Police and a mental health professional were sent to the man’s house, where he “appeared to exhibit psychotic and delusional behavior and was determined to be a danger to others,” officials said. Among the man’s claims: Police say he told them he needed to arm himself against Microsoft founder Bill Gates.

The man was taken into custody and placed on a 72-hour psychiatric hold. He is on probation for a drunk driving conviction, and not allowed to own guns until 2025, according to police.

The city attorney’s office was able to seize the man’s unregistered weapons and say they will prevent him from obtaining others through San Diego’s Gun Violence Restraining Order program.

“Stress from the COVID-19 public health crisis is exacerbating anxiety and mental health struggles for many,” City Attorney Mara W. Elliott said. “Thanks to public vigilance, police were able to safely intervene and remove firearms from someone who presented a danger to himself and others before he resorted to violence.”