TWO SIBLINGS CHARGED AFTER EXPLOSIVE DEVICE SAT UNDETECTED FOR DAYS AT MACDILL AIR FORCE BASE

A device placed near a public entry point became a bomb threat reported on March 10th, but it didn’t lead to anything responders could find. Until six days later, when an Air Force service member found a suspicious package near the visitor control center at MacDill Air Force Base, an entry point routinely used by civilians and base personnel.

Federal investigators determined the package contained materials consistent with an improvised explosive device, or IED. It was secured by authorities without detonating and sent to an FBI laboratory in Huntsville, Alabama, for analysis.

The device did not detonate, but according to U.S. Attorney Gregory Kehoe it “could have potentially been very deadly.”

A 911 Call That Lacked Critical Detail

Investigators say the initial warning came from the person now accused of placing the device. 20-year-old Alen Zheng called 911 on March 10th to report a bomb, but did not give a specific location. The FBI later traced this call to a "burner" phone Zheng reportedly purchased at a Best Buy, with store surveillance footage confirming the transaction.

Base personnel searched but didn’t find anything until March 16th, six days later. Zheng fled to China after allegedly placing the device. Alen Zheng now faces 40 years in prison if convicted of attempting to damage federal property, along with both making and possessing the explosive device.

His sister, Ann Mary Zheng, is staring at a sentence of up to 30 years if found guilty of witness tampering and being an accessory after the fact to the crime, after allegedly selling the car her brother used to drop off the package, according to Kehoe.

Travel, Vehicle Sale, and Return to the U.S.

Arrest paperwork says that after the device was placed, Zheng and his sister, 27-year-old Ann Mary Zheng, sold a vehicle tied to the investigation prior to the siblings leaving the United States, fleeing to China.

According to U.S. Attorney Kehoe, federal agents tracked down the vehicle at CarMax. Although it had been professionally vacuumed and cleaned, forensic teams recovered residue matching the explosive components found in the IED.

Ann Mary Zheng returned to the U.S. on March 17th, one day after the device was found, and was taken into custody. Her brother Alen Zheng remains overseas.

Authorities have not outlined an extradition timeline for Alen, though investigators are closely examining the sequence of events carried out by the Zheng siblings.

Federal Charges Outline the Alleged Conduct

On March 26th, a federal grand jury indicted both siblings charging Alen Zheng with attempted destruction of government property using explosives, manufacturing an explosive device, and possession of an unregistered destructive device.

His sister, Ann Mary Zheng is charged with accessory after the fact, and evidence tampering. Prosecutors say the charges reflect both the alleged placement of the device and actions taken afterward to conceal involvement.

Investigators cite a mix of physical and digital evidence that includes surveillance footage linking a vehicle to the area near the visitor center, phone records tied to the 911 call, explosive residue recovered from a cleaned vehicle, and materials consistent with explosive components recovered during a residential search.

The device itself was sent to an FBI laboratory in Huntsville for forensic analysis. Authorities have not released a detailed technical breakdown yet.

At this stage, these details remain allegations outlined in official indictment paperwork and have not yet been tested in court.

Why MacDill Air Force Base Carries Strategic Weight

MacDill Air Force Base is the home of the United States Central Command and the United States Special Operations Command. The base plays a critical role in U.S. military operations and overall readiness. The package was found outside a public-facing entry point, not inside restricted operational areas. Even so, proximity to these commands raises the stakes of any potential security incident.

This case highlights how base security is structured with the bulk of protection heavily reinforced inside the installation, with controlled but more accessible access points at the perimeter. Officials have not indicated any ongoing threat to personnel or operations at MacDill Air Force Base.

Where the Case Stands

Incidents involving suspected explosive devices on U.S. installations are rare. Still, the timeline in this case, particularly the gap between the initial report and the discovery, underscores the importance of reporting suspicious activity near access points, something service members are routinely trained to do.

Investigators have not yet publicly identified a motive for siblings, Alen and Ann Mary Zheng, both of whom are U.S. citizens. Authorities are reviewing the details of this case for any ideological or foreign-directed efforts.

Officials have not said whether the device was fully operational or partially constructed, and authorities have not identified additional suspects or involvement of a broader network.

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