Investigators say a third Michigan man is now facing charges in a plot to stage a terror attack on Halloween. He traveled to an amusement park in the midwest to scout the location, they said.

Ayob Nasser, 19, was arrested on Wednesday. He is accused of participating in the planning of a possible attack on LGBTQ+ bars in suburban Detroit that was inspired by the Islamic State, federal authorities have said.

Nasser, his brother Mohmed Ali and Majed Mahmoud are charged with conspiracy to provide material support and resources to a designated terrorist organization and receiving and transferring guns and ammunition for terrorism, according to court documents.

Mohmed Ali and Majed Mahmoud were arrested on Friday. Investigators say two minors, identified only as Person 1 and Person 2 in court documents, were also involved in the discussions.

“We will not stop. We will follow the tentacles where they lead. We will continue to stand guard with the FBI against terrorism,” said US attorney Jerome F Gorgon Jr in a statement.

It was unclear whether Nasser has an attorney. Two attorneys representing Ali and Mahmoud declined to comment when reached by phone on Wednesday evening, and both said they are reading through an amended 93-page complaint filed in federal court. One of the attorneys, Amir Makled, over the weekend seemed to wave off the allegations, saying they were the result of “hysteria” and “fear-mongering.”

Ali and Mahmoud made brief appearances in federal court on Monday and will remain in custody at least until a 10 November detention hearing.

FBI agents had surveilled the group for weeks, even using a camera on a pole outside a Dearborn house, according to the court filing. Investigators also obtained access to encrypted chats and other conversations and scoured social media posts.

According to the court filing, investigators searched the residences of the group, an auto repair shop operated by Ali and Nasser’s family and a storage unit rented by Ali. Authorities found AR-15-style rifles, ammunition, loaded handguns and GoPro cameras, as well as tactical vests and backpacks.

Five cellular devices were also seized, the FBI said.

Investigators said that Ali, Mahmoud and one of the minors, Person 1, visited bars in Ferndale, a northern suburb of Detroit, despite all being under the legal drinking age. The city attracts tens of thousands of people to its annual Pride parade.

Nasser and Person 2, a minor, traveled twice in September to “an amusement park in the midwest, approximately three hours from Dearborn, Michigan”, court documents say, citing phone records and surveillance footage. Investigators say a computer at the home of Nasser and Ali revealed that someone had searched “is it crowded on halloweekend” at the amusement park.

The documents do not name the amusement park. But Cedar Point, an amusement park near Cleveland, Ohio, appears to match the description and Halloween hours outlined in the complaint.

In the new court filing, investigators said a group chat between the men indicates reference to a Halloween attack with repeated references to pumpkins and pumpkin emojis. In the group chat, one of the unnamed conspirators wrote “American Jewish Center,” and Nasser responded “pumpkin sounds good now.”

The court filing says Person 1, the minor, regularly consulted the father of a “local Islamic extremist ideologue” about when to commit a “good deed.”

Phone records also showed members of the group looked up information on various mass killings, including the 2016 Pulse nightclub shooting, the 2022 Buffalo supermarket shooting, the 2023 Nashville Covenant School shooting, and the deadly 2025 New Orleans truck attack.