The listing said, "For Sale: Lot of Guns," and Serafin Lorenzo was interested.

The 53-year-old who went by Danny liked to buy expensive items and resell them for a profit, and the cache of guns he found on ARMSLIST.com offered the bargain he was looking for. There were four Glocks, a couple of 9mm pistols and nine high-powered rifles. The Florida seller, a guy named "Jeremy," wanted just $3,000 cash.

"Leaving the country soon," Jeremy's listing said. "Looking to sale [sic] all my guns as I can't take them with me."

Less than 24 hours after inquiring, Lorenzo and his wife, Deana, 51, were on the road from Brooksfield, Florida, late on the night of April 9, 2018, to meet Jeremy at an address just off Corkscrew Road in Estero, about 190 miles south. At 10:44 p.m., Lorenzo texted: "I'm at the church."

Minutes later, the Lorenzos were dead.

Police wouldn't find Lorenzo and his wife in the church parking lot until the next morning. Next to Lorenzo's body was a bill of sale for 15 firearms — and a cellphone that would send the FBI down a wild path stretching halfway around the world leading to the alleged perpetrators.

Starting with little more than the online gun listing and the texts to Lorenzo from a Walmart burner phone, authorities say they learned the gunmen were two ex-Army soldiers bent on joining right-wing paramilitary groups involved in armed conflicts worldwide. The gun listing was true in one respect: They were leaving the country — to go to Venezuela to fight the government with the resistance, prosecutors say. The guns were coming with them. They allegedly just wanted the Lorenzos' $3,000 to fund the journey.

On Wednesday, federal prosecutors identified the ex-soldiers as Alex Zwiefelhofer, 22, and Craig Lang, 29, in an indictment charging them with a host of federal crimes tied to the double homicide in Estero, just south of Fort Myers. The 33-page complaint traces the soldiers' zigzagging paramilitary campaigns across the world, starting in Ukraine and, in Lang's case, finally to Venezuela, revealing how some military veterans have been drawn to extremist causes overseas.

Caught in the crosshairs were the Lorenzos — in an ambush plot that the FBI says Zwiefelhofer and Lang stole straight out of a movie clip they studied on the internet.

"A review of this video was important," an FBI special agent wrote of the unidentified movie, "in that the homicide scene in Estero, Fla, was consistent with the tactical approach of shooters and trajectory of the gunshot defects depicted in the movie."

Lang was also named in a separate federal indictment this week as the alleged "mentor" to Army Pfc. Jarrett William Smith, who is accused of providing recipes for explosives online and talking about killing Antifa protesters and bombing CNN, the network reported. Smith had hoped to join Lang as a fighter in another extremist unit in Ukraine, where Lang currently lives, according to that complaint.

Lang is now in custody in Ukraine, Radio Free Europe reported Thursday, citing Lang's associates and local fighters. Zwiefelhofer was arrested earlier this month in Wisconsin, and both are now awaiting extradition to Florida. Attorneys for the men are not yet listed in federal court records. An uncle of Lang's Ukrainian girlfriend, Ihor Skritsky, told Radio Free Europe that Lang "denies any involvement."

Zwiefelhofer and Lang were used to fighting behind the same lines.

They met after joining the same battalion in the Right Sector, a far-right Ukrainian nationalist paramilitary group dedicated to battling Russian separatists on eastern Ukrainian soil. Itching for combat, they were enamored by the group's stated goal of removing Ukraine from Russian or European Union influence. "These people f------ want change," Lang, who had completed two tours in Iraq and one in Afghanistan, told Vice in a 2016 story about why right-wing Americans were joining the Right Sector. The Ukrainian government had banned the group from the battlefront.

Lang joined in 2016 after his life fell apart in the U.S. In 2014, he went AWOL from Fort Bliss in El Paso and drove cross-country to North Carolina in a car stocked with assault rifles and body armor, saying he wanted to kill his pregnant wife, Vice reported. Lang was dishonorably discharged from the Army and, after spending time in jail for the incident, couldn't get a job, he told Vice.

So, he went back to war. Months later, in September 2016, Zwiefelhofer would go AWOL from the Army too, prosecutors say, and would encounter Lang upon arriving in Ukraine.

But after a while, Lang and Zwiefelhofer decided they wanted to change course. In June 2017, they headed to South Sudan to fight al-Shabab, a jihadist terrorist organization allied with al-Qaeda. They made it to Kenya with one other former Army soldier — only to be captured by the Sudan Peoples' Liberation Army trying to cross the border without papers. Stuck in a Kenyan jail, writing from a smuggled "prison pocket phone," Zwiefelhofer complained in a July 2017 Facebook post: "so, week six of African jail. just contracted cholera."

He and Lang would ultimately get deported back to the United States, each arriving at separate airports. But more jail awaited Zwiefelhofer upon his arrival in Charlotte that August. While interrogating him over his paramilitary endeavors in Ukraine and South Sudan, U.S. Customs and Border Protection agents at the airport also found child porn on his phone, according to the complaint. He was held in jail for months before being released on bond in November 2017 — only to fail to turn up for his hearings.

He and Lang were too busy plotting their next overseas war-zone mission, according to the complaint. This time, prosecutors said they planned to hijack a yacht in Miami and sail south to join the armed conflict against the Venezuelan government.

On Zwiefelhofer's Internet history, the FBI discovered one question he asked Google: "How to Smuggle Myself to South America."

The FBI says it found the details of the plot in numerous Facebook messages he and Lang exchanged in the weeks and days leading up to the Lorenzo killings.

On April 4, 2018, the two men met at a Greyhound bus station in Florida and together headed to Miami, prosecutors say. Lang brought the cache of guns from home in Arizona. Once checked into the La Quinta Inn, they planned to hit up an Army surplus store for body armor, meet with a yachting company to tour some boats that would make ideal candidates for theft ― and finally, put up the fake gun listing to set up the deadly robbery, according to the complaint.

Just before setting it all in motion, the FBI said, they replayed the movie clip over and over from their hotel room — and then took selfies in Hawaiian-style shirts, the FBI wrote.

The text message the duo was waiting for came in at 2:10 p.m. on April 9: "I have cash on hand," Lorenzo wrote. "Mine is a sure deal."

By the time police discovered the Lorenzos' bodies in the church parking lot, Zwiefelhofer and Lang were long gone. One of Lang's ex-Army associates would later tell the FBI that Lang and Zwiefelhofer never carried out the boat hijacking plot, instead fleeing to Washington state, as far away from the crime scene as possible.

Zwiefelhofer ultimately returned to Wisconsin. But Lang hadn't given up on the plan to go to Venezuela or even back to Ukraine, prosecutors said. After lying low for a while, Lang met up with his ex-Army soldier associate, identified as "M.S.M." in the indictment, who agreed to go with him to go south.

The new plan: Sell the guns used in the Florida killings to two men in exchange for their identities and social security numbers. That way, prosecutors said, they could obtain fraudulent passports and flee the United States for Ukraine or South America, according to the indictment.

It worked.

Lang and M.S.M. managed to fly to Bogota, Colombia. The resistance group Lang allegedly wanted to join had a safe house in the mountains of Cúcuta, Colombia, and they were planning to cross the border to fight the Venezuelan government. Lang got on a bus, M.S.M. told the FBI, and that was the last time M.S.M. saw him. M.S.M. got cold feet.

"He left Lang in Bogota because M.S.M. did not want to kill people," the FBI reported in the complaint.

Lang faces federal passport fraud charges in a separate indictment filed last month. In that case, a man named Matthew Scott McCloud is indicted in the conspiracy with Lang. According to Missouri authorities, McCloud fled to Ukraine to avoid prosecution for felony stealing, then traveled to Colombia, Mexico and back to the United States, the Columbia Daily Tribune reported.

As for Zwiefelhofer, the Bureau of Alcohol, Tobacco, Firearms and Explosives arrested him in May in Chippewa Falls, Wisconsin, after he allegedly lied on an ATF form while trying to buy a gun. The FBI obtained a warrant to search his home, finding the distinctive Hawaiian shirt they allege he wore in Miami, and the laptop containing his search history.

The gun listing, they said, was created under the name Jeremy on that same computer

During an interrogation, Zwiefelhofer told the FBI about his excursions with Lang in Ukraine. He told the agent about their plans to meet in Miami, how they wanted to take a boat to Venezuela.

But when asked about the burner phone authorities linked back to him, the one that lured Serafin and Deana Lorenzo to their deaths, Lang denied any wrongdoing. He said he bought the burner phone at Walmart because they ran out of money to stay at La Quinta Inn and had to spend the night in a dog park, where the sprinkler system came on overnight and ruined his cellphone.

He said the story ended there.

