Authorities arrested Amiremad Nayebyazdi in Oklahoma City, after he reportedly told his sister that "hundreds of people" would die in the city.
According to a Monday report by KOCO-TV, Nayebyazdi contacted his sister, who lives in Iran, to deliver the news.
What are the details?
Authorities said that Nayebyazdi told his sister that "hundreds of people are going to die in Oklahoma City, and something very large is going to happen."
Nayebyazdi reportedly had been seen at the Oklahoma City National Memorial, taking photos from multiple vantage points on several occasions. Memorial security was able to observe the man's vehicle tags, so he was more easily identifiable.
Nayebyazdi had several other arrests under his belt, including possession of a controlled dangerous substance, driving under the influence, and public intoxication. He also had reportedly been taken into protective custody during a 2014 incident for a mental health evaluation.
The suspect previously worked for an Oklahoma City oil company, and possesses a degree in petroleum engineering.
Local authorities said that they received a telephone call on Thursday from a concerned California citizen, who revealed that Nayebyazdi had left the recorded message — which was "loosely translated" by the tipster — for his sister.
The message reportedly said, "Hundreds are going to die in Oklahoma City, something very large is going to happen, it will be on the news, and don't tell mom and dad until it is seen on the news."
The California tipster said that they'd received the information from a high school friend living in Germany. All four parties had reportedly grown up together.
So how did authorities arrest Nayebyazdi?
The FBI, along with local authorities, a bomb squad, and a tactical team, visited Nayebyazdi's home. A K9 officer inspected Nayebyazdi's vehicle, but found no traces of explosives.
When officers approached Nayebyazdi's apartment, he reportedly opened the door and permitted officers to come in.
Authorities reported that Nayebyazdi admitted to leaving his sister the message, which led officers to question whether Nayebyazdi was pointing to an explosive device.
Nayebyazdi answered in the affirmative, and said that he "hears things" — but that he did not make any explosive devices. Nayebyazdi added that he only told his sister that this purported incident would occur.
Nayebyazdi was adamant that he did not want to hurt people, and had not placed any explosives anywhere.
However, he admitted to having "problems," according to KOCO. Nayebyazdi also admitted to having been diagnosed with mental issues and had been prescribed medication, but he hadn't been taking it.
While at Nayebyazdi's home, a crisis intervention officer responded to the scene and performed a mental check on Nayebyazdi, who was placed in protective custody. He was later taken to St. Anthony Hospital for a more in-depth evaluation.
A search of the man's property did not turn up any explosives, according to authorities, but an arrest warrant was issued for Nayebyazdi for a charge of threatening to kill by use of explosive.