CHICAGO (WLS) — Federal prosecutors in Chicago have arrested and charged an eighth suspect accused of having ties to a group that allegedly planned an attack connected to the White House UFC event earlier this month, the Department of Justice said.
The video in the player above is from a previous report.
Alexander Mercado, 20, of Chicago, was taken into custody Thursday and now faces a federal obstruction of justice charge.
During his first court appearance and arraignment Friday, Mercado entered a not guilty plea and was seen wiping away tears after doing so.
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Prosecutors allege Mercado deleted the Signal messaging app from his phone after an FBI agent contacted him on June 13, the day before the UFC event, according to the DOJ.
The indictment says the agent asked Mercado during a phone call whether he intended to travel to Washington, D.C., to assist with the attack. Mercado denied having such plans.
Authorities allege Mercado later failed to answer additional calls from investigators. They also determined he had uninstalled Signal, which deleted message-related data tied to the group from his phone.
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Seven additional defendants have previously been charged in connection with the alleged plot.
Prosecutors on Friday asked that Mercado remain in custody, arguing he was the “administrator” of the group, engaged in recruitment efforts, contacted a high-ranking member who remains at large, and poses risks of obstruction of justice and flight. They also argued Mercado has an unstable living situation, noting he recently moved and lives with his mother, who was the alleged victim in a domestic battery case in October 2025 involving Mercado that was later dismissed.
The defense countered that the family’s recent move does not make his housing unstable, noted the domestic case was dropped shortly after it was filed, and argued there is no evidence Mercado knows the identities of other group members because the platform is anonymous. The judge said he does not consider Mercado a flight risk based on his housing situation alone but found the government met the legal standard to hold a detention hearing, which is set for Tuesday.
Prosecutors also moved to unseal the indictment, and the case has been assigned to U.S. District Judge John Blakey.
Mercado faces up to 20 years in prison, if convicted.
An attorney for Mercado could not immediately be reached as of Friday afternoon.
ABC News contributed to this report.
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