In 2012, Loeun was convicted on a felony charge for possession of marijuana, which under federal law causes legal residents to lose their immigration status. After Loeun and his family traveled to Cambodia in 2015, U.S. Customs and Border Protection (CBP) denied him reentry, detained him at San Francisco International Airport, and threatened to deport him. Loeun was then served with a notice to appear for deportation proceedings due to his 2012 cannabis conviction and had his green card seized, Loeun’s lawyer, Anoop Prasad, told NBC News. "He, at that point, was obviously really scared. He'd seen other folks, others in the Cambodian community, get detained for months and years and then get deported with nothing but the clothes on their backs," Prasad said. "He decided, rather than risking being arrested or detained, he was just going to self-deport. His rationale was, you know, he's a single parent with three kids. He didn't want to put them through him being locked up for a really long period.”

According to NBC News, while an attorney with Immigration and Customs Enforcement (ICE) acknowledged Loeun “might be a U.S. citizen” and requested the case be dismissed at a 2018 hearing, Loeun, who was not in attendance at the hearing, was not made aware of this.

After self-deporting to Cambodia, a country unfamiliar to him beyond his family visits, Loeun started a new life in the country he fled as an infant. He washed motorcycles for $8 a day before starting a wedding planning business with a woman he married there, the Chronicle reported. It wasn't until November 2019, when he attended attorney Prasad's legal workshop in the capital city of Phnom Penh, that Loeun learned he was a U.S. citizen.

Sarah Pierce, a policy analyst for the Migration Policy Institute, told the Chronicle derivative citizenship is a complex concept in immigration law, making it difficult for foreign nationals to know whether they have obtained citizenship, especially when the government fails to notify new Americans. "It's very understandable that foreign nationals themselves wouldn't know whether they had acquired citizenship, especially if they have other IDs and they're able to get by with those other IDs and they haven't been doing a lot of traveling," Pierce said.

A CBP spokesperson told the Chronicle that the department does not comment on pending immigration cases.

Loeun’s case is not isolated. Prasad told NBC News that Loeun is the third Cambodian to have been mistakenly put through deportation proceedings. "The United States, of course, may not deport its own citizens, but it happens far too often," he said. "As long as the United States follows mass deportation policies, we know this will continue to happen.” According to NBC News, the deportation of Cambodian immigrants has increased by 279% in the past two years, and many of those targeted by ICE arrived in the U.S. legally as refugees.

What happened to Loeun is an unfortunate reality as the Trump administration continues to target immigrant communities, but injustice against immigrants is an issue embedded in U.S. history. Mass deportations took place long before Donald Trump took office in 2017. According to data from the Migration Policy Institute, more than 12 million people were deported during the Clinton administration, 10 million during the (second) Bush administration, and 5 million during the Obama administration.

The joy of overcoming such horrors can be felt in all-too-rare reunions.

x SFO has been at the center of so many local immigration stories in recent years. Tonight, friends & fam await the arrival or Sok Loeun, who left to Cambodia in 2015 after being targeted for deportation, despite being a US citizen (unbeknownst to him). pic.twitter.com/sGYoCvwNU4 Ã¢ÂÂ Tatiana Sanchez (@TatianaYSanchez) January 30, 2020

While Loeun’s return is worthy of celebration, we must keep fighting so that one day, more immigrant families are united than separated.