A former Wright-Patterson Air Force Base subcontractor and Air Force Reserve major ― who once claimed he was more dangerous than deadly domestic terrorist Timothy McVeigh — was sentenced to nearly three years in federal prison for illegal possession of a firearm suppressor and…a missile warning system?

It was calls to police from a neighbor in 2015 who said that Joel B. Montgomery, an Air Force Reserve veteran and former sensor technician at the base, had been shooting firearms at their property that triggered his eventual prison sentence.

Montgomery pleaded guilty to two counts against him in December and was sentenced to 33 months in prison this week.

Former VA official sentenced for federal contract bribery scheme Official told undercover agent he needed bribes, "so I can have my Christmas..."

It seems the electrical engineer was building a complex home defense system. Montgomery, according to court records, was working with range of items, from the low tech -- pressure cookers, BBs and smokeless powder -- all the way to sophisticated anti-missile devices.

When federal agents searched his Spring Valley, Ohio home on October 26, 2017 they discovered the AN/AAR-47 Missile Warning System and Control Countermeasure Set Display Unit.

Mostly used on helicopters or transport aircraft, the 32-pound system is mounted on platforms such as the V-22 Osprey. It is built by Northrop Grumman and designed to protect aircraft from infrared-guided missile threats, laser-guided threats and unguided munitions. The system provides audio and visual warnings to the pilot when it detects a threat, according to the company’s website.

It then sends countermeasure signals to the control unit to defeat incoming threats.

× Fear of missing out? Sign up for the Air Force Times Daily News Roundup to receive the top Air Force stories every afternoon. Thanks for signing up. By giving us your email, you are opting in to the Air Force Times Daily News Roundup.

Former Air Force Reserve Maj. Joel B. Montgomery, who also worked as an engineer at Wright-Patterson Air Force Base, was sentenced to nearly three years in prison for possession of an illegal firearms suppressor and missile detection system at his Ohio home. (Green County, Ohio Sheriff's Office)

Court documents do not indicate what Montgomery’s plans were for the device. But other statements he made or were attributed to him show he had planned to set up trip wires and rig his home with explosives should agents infiltrate the residence.

A not-so-neighborly dispute over allegations that Montgomery was shooting firearms at a nearby property put the 50-year-old engineer on police radar.

Greene County, Ohio sheriff’s deputies searched Montgomery’s home in June 2015, seizing 177 firearms that were scattered throughout the four-bedroom home situated on a heavily wooded five-acre lot.

Among those firearms, they found a suppressor, illegal for private ownership without specific licensing and fees, according to court documents.

Two neighbors told police after the SWAT search that they feared what Montgomery would do once he found out about the visit.

One of those neighbors showed police a text message purported to be from Montgomery, that read, “If I wanted you gone, they wouldn’t find the body.”

Weapons were later returned to Montgomery.

Other neighbors, however, later told officials that they didn’t fear Montgomery and had known him for years.

After the search, the Bureau of Alcohol, Tobacco and Firearms, along with FBI agents began monitoring Montgomery’s actions through recorded calls with a confidential information who’d been friends with Montgomery for decades.

In a series of calls made in February 2016, Montgomery told the friend that he had planted VX nerve agent gas in three different cities and had multiple passports to flee the country if he was arrested. He also said he was “rigging up” his home in case federal agents raided the residence.

Montgomery said he was more dangerous than homeland terrorist bomber Timothy McVeigh, involved in the 1995 Oklahoma City bombing that killed 168 people, and the terrorist group ISIS.

In the calls, officials allege he also made threats against the federal prosecutor in his case and another man named Jim, possibly a federal agent, saying he would cripple the man and kill his two sons, according to court documents.

In a detention hearing, U.S. Magistrate Judge Michael Newman said, “I am greatly troubled by the voicemail and text message here,” before ruling to keep Montgomery in custody.

But a federal defense attorney would later tell a judge that few of these statements had any truth to them.

She characterized the calls as “ramblings without any teeth to them.”

Then, in September 2017, ATF agents got a “cold call” from another informant who shared text messages and voicemails from Montgomery.

On October 18 of that year, an FBI SWAT team went to Montgomery’s house, calling out on the loudspeaker system for him to surrender. Two of his teenage children came to the door without resistance. The agents searched the home, finding more than 200 firearms strewn about the house.

He was arrested in another location.

They also found what appeared to be a homemade mortar tube, mounting device and base plate in the basement. In the kitchen they found a pressure cooker and a combination of explosives precursors, explosives and weapons’ silencer manuals in Montgomery’s office, along with a pile of empty beer cans near the front door.

Montgomery had racked up multiple convictions from 2003 to 2016, including DUIs, domestic violence, public intoxication and weapons charges, according to court records.

His phone angry ramblings weren’t limited to targets of his frustration, according to court testimony -- he also embellished information about his friends.

Army Green Beret veteran Donald Austin Jr., a neighbor of Montgomery’s for decades, testified on the man’s behalf at another detention hearing leading up to his scheduled trial.

Federal prosecutors asked Austin if statements made by Montgomery that Austin had “700 confirmed kills” and had done mercenary work in Angola in the 1980s were true, according to court transcripts.

They were not, Austin said. Montgomery was a former weapons sergeant with a Green Beret team in Vietnam who later did work in Germany in the 1980s. And he had only 16 confirmed kills, Austin testified.

In the search, agents found the AN/AAR-47 Missile Warning System and a Control Countermeasures Set Display Unit.

Montgomery tested and recorded data for sensors at Wright-Patterson, according to court documents. The system he had at his home was government property that he had kept “for personal use,” according to court documents.

In a federal lawsuit that Montgomery filed in 2007 against General Dynamics, the Pentagon, the Air Force and an individual, he claimed that slanderous statements had caused his company, M and M Aviation, to lose its contract with the Air Force that involved tactical and theater missile warning systems.

The claim he said that he worked from 2002 to 2004 as the program manager over the Electro-Optical Materials Intelligence Group of GDAIS, a military contractor.

A February 2004 memo laid out serious concerns from multiple employees.

Some included statements that Montgomery had arguments with co-workers, in which he claimed to have classified documents in his home and a live grenade in a green ammunition box in his work office. He also claimed to carry and store weapons at his work office, according to court documents.

In 2005, Montgomery’s security clearance was suspended.

In November 2006 an Air Force colonel noted they she had “grave concerns” that then-Maj. Montgomery could perform his duties, even at an unclassified level and he was moved to the Inactive Ready Reserve.

In his 2007 lawsuit, Montgomery says the allegations were false, libelous and slanderous and caused him to lose his job.

In a subsequent lawsuit, filed in 2013, Montgomery sued the FBI, the Air Force and the certain individuals, claiming that they had conducted illegal surveillance on him, using a GPS device on his car a camera in the office where he worked and a listening device in his home.

At that time, 2006 to 2007, he worked for the National Air and Space Intelligence Center at the Air Force Research Laboratory, according to court documents.

In the lawsuit, Montgomery claimed that one of his friends noticed a bundle of wires hanging from underneath his 1992 Nissan truck. They then found a GPS tracker, he alleges.

Montgomery said he reported it first to his commanding officer then to the FBI. He later removed the device himself. He took a photo of it, which he included in his lawsuit filing.

He says FBI agents demanded the device but wouldn’t provide a him documentation that they had received it.

At around that time he says he found a video camera installed under a ceiling tile in his work space on Wright-Patterson AFB. He says then used a spectrum analyzer and found an audio wire tap near his computer in his home.

Both lawsuits were dismissed in 2014.

In his criminal case, Montgomery originally faced federal explosives charges and threat-related charges along with those that he pleaded guilty to, but the explosives and other charges were dismissed as part of his plea agreement.