MacDill Remains on Alert as Indictments Drop in Failed Bomb Attack

MacDill Air Force Base, Fla., home of U.S. Central Command, remains on heightened security status after the Justice Department announced two indictments stemming from an attempted bombing at the base.

Alen Zheng, 20, of Land O’Lakes, Fla., was charged March 25 with attempting to detonate a homemade bomb at the visitor’s center at MacDill on March 10. Zheng is now in China, FBI Director Kash Patel said March 26 in a post on the social media platform X.

Zheng’s 27-year-old sister, Ann Mary Zheng, also of Land O’Lakes, was indicted as well. She is accused of trying to help her brother in the aftermath, hindering his potential arrest, trial, and punishment. The FBI alleges she helped to alter or destroy a Mercedes car in an effort to ensure it could not be used as evidence in her brother’s prosecution. Patel said Ann Mary Zheng is in custody.

According to the Justice Department, Alen Zheng attempted to detonate an improvised explosive device the evening of March 10, but it failed to detonate. Six days later, on March 16, the alleged bomb was discovered, prompting the base to temporarily close its visitor’s center and a nearby gate while the device was defused.

The following day, MacDill announced it had raised security to Force Protection Condition, or FPCON, Charlie—typically used when a terrorist or other hostile incident occurs at an installation, or if intelligence indicates an increased threat risk to a specific Defense Department organization or facility.

A spokesman for MacDill on March 27 confirmed the base is still at FPCON Charlie, but declined to comment on what additional measures were in place or the reasoning for maintaining a heightened force protection level now.

Retired Air Force Col. Patrick Donley, a former security forces officer and now director of the the Air & Space Forces Association’s Doolittle Leadership Center, said other bases may also be keeping a close eye on potential threats and security levels given the ongoing conflict with Iran is raging.

“Just the fact that we’re at war, everybody’s going to be a little ramped up as they begin to assess the [security] picture,” Donley said.

FPCON Charlie could mean assigning more security forces and additional patrols and potentially arming them with rifles instead of pistols, Donley said. Additional security forces could be assigned to specific locations, such as gate access points, and the base could adopt higher screening standards or different procedures for vetting people or vehicles coming on base, he said.

For example, a recent visitor to MacDill described having to open the hood of his car before being granted entry.

Bases can also supplement their security personnel with Airmen assigned from other jobs on base working as security “augmentees,” Donley said. Bases also opt for an intermediate security condition, colloquially called as “Bravo-plus,” with increased security measures that still fall short of FPCON Charlie. 

“The big difference with Charlie is that … there’s something more specific that gives them a sense of, they need to be postured to act very quickly,” Donley said March 27. “It’s all about trying to have the force necessary [and] ready to go should something actually happen.”

But Donley cautioned that FPCON Charlie is not meant to be a long-term measure. Simply having ongoing hostilities with Iran wouldn’t lead to a higher security level, he said. But if a base a threat is identified and considered ongoing, the level can hold.

“Charlie can’t be sustained for long periods of time without a pretty dramatic consequence to the base,” Donley said. “It requires so many extra people, and it slows things down. Typically what you do is ramp up while the threat is there, and then you quickly come out of that, instead of it being a posture that you stay at long term.”