Brother and Sister, Both U.S. Citizens, Indicted in Explosive Device Incident at MacDill Air Force Base; One Suspect in China

By Alex Nitzberg and Alexandra Koch

Published: 2026-03-26

A brother and sister, both U.S. citizens, have been indicted in connection with an explosive device found outside MacDill Air Force Base in Florida. Authorities state that Alen Zheng is believed to have placed the device and subsequently traveled to China. His sister, Ann Mary Zheng, faces related charges. Their mother is in Immigration and Customs Enforcement (ICE) custody after reportedly telling investigators that her son admitted involvement in the incident.

According to the FBI, Alen Zheng faces charges of attempted damage to government property by fire or explosion, unlawful making of a destructive device, and possession of an unregistered destructive device. These charges carry a maximum sentence of 40 years in prison. Ann Mary Zheng has been charged with accessory after the fact and tampering with evidence, which carry a maximum sentence of 30 years in prison.

Court documents indicate that Ann Mary Zheng is accused of concealing or damaging a 2010 Mercedes-Benz vehicle to impede its use in the investigation. Prosecutors allege that on March 11 — the day after the device was reportedly placed — the siblings attempted to sell the vehicle to CarMax. Although the vehicle had been cleaned, investigators later found trace amounts of explosive residue inside it.

The indictments were unsealed on Thursday morning. U.S. Attorney for the Middle District of Florida Greg Kehoe outlined the sequence of events during a news conference that afternoon.

On March 10, authorities allege that Alen Zheng placed an improvised explosive device (IED) in a secluded area outside the base's visitor center. Minutes later, an individual matching his description reportedly made a 911 call stating that a bomb had been planted but declined to provide its precise location. The device did not detonate.

Members of the Tampa Police Department blocked traffic along South Dale Mabry Highway near the main entrance of MacDill Air Force Base following a report of a suspicious package at the gate.

On March 16, an Air Force airman located the device outside the MacDill visitor center, six days after it was allegedly placed. To preserve evidence, authorities secured the device and transported it by Pasco County Sheriff's Office helicopter to the FBI's Terrorist Explosive Device Analytical Center (TEDAC) in Huntsville, Alabama.

During the news conference, Kehoe described the device's construction, noting that it involved components assembled in a manner consistent with analyzed devices. He stated, "Anytime somebody puts an IED together — and I spent a lot of time in Iraq and I saw a lot of IEDs — there always is a level of professionalism. And quite a bit of professionalism when they end up being deadly. … [The explosive] certainly could have caused significant damage to people that were in the range."

An FBI analyst handled an envelope containing IED evidence at the TEDAC facility in Huntsville, Alabama.

Investigators traced the 911 call to a burner phone purchased by Alen Zheng at a Best Buy store, using security footage to confirm the transaction. A search of his residence yielded components matching those in the recovered device.

The siblings departed for the People's Republic of China on March 12, two days after the incident, according to authorities. Ann Mary Zheng was detained upon her return to the United States at a Detroit airport on March 17.

Police officers blocked traffic near the main entrance of MacDill Air Force Base in Tampa, Florida.

The siblings' mother told investigators that her son had confessed to her about the plot. She is currently in ICE custody pending deportation proceedings due to a visa overstay but has not faced criminal charges as of Thursday afternoon.

Authorities have not publicly disclosed a motive for the incident or any connections to foreign governments. Kehoe stated that the suspects "obviously felt quite strongly about something or anything that the United States government was doing."

FBI Director Kash Patel issued a statement describing the indictments as "the result of tremendous investigative work from our FBI teams and great coordination from our state, local, and federal partners across the board." He added, "No one who targets our brave service members and military facilities will ever get away with it — and this FBI will pursue all those responsible for the incident at MacDill Air Force Base to the ends of the earth."

FBI Director Kash Patel commented on the indictments following the news conference.

Officials also unsealed a separate indictment against Jonathan James Elder in connection with an unrelated threat. On March 18, Elder allegedly telephoned the base, making explicit threats and referencing a "surprise at MacDill Visitor Center." Authorities tracked him using cell phone and Facebook data, leading to his arrest at a care facility. He faces up to 10 years in prison for making a threat involving an explosive device.

Kehoe issued a statement during the news conference, saying, "If you harm somebody, if you threaten to harm somebody, or if you decide that you are going to get on the telephone and you're going to telephone a threat to someplace like MacDill Air Force Base, … you will be charged by this office. We are simply not going to tolerate this type of conduct here in the Middle District of Florida."

MacDill Air Force Base is home to the headquarters of U.S. Central Command (CENTCOM) and U.S. Special Operations Command (USSOCOM), which oversees special operations forces across the Department of Defense.

This is a developing story. Additional updates will be provided as more information becomes available.

Alex Nitzberg is a writer for Fox News Digital.

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