Looking back at the jokes now, the lines like "I hate you, Americans" from a young man named Zulfi Hoxha don't seem so funny now.
Hoxha, now 25, was a bus boy when he worked at a Margate, New Jersey, restaurant with Joseph Cacia.
"We used to joke around like, 'We know you can’t stand us Americans.' And he would laugh like, haha, 'Yeah, we can’t stand you Americans,'" Cacia told NBC10. "But you didn’t think he was serious. You thought he was playing along."
No one is laughing anymore. Hoxha is now in Syria, a "senior commander" with ISIS, also known as the Islamic State, according to federal court documents and his mother in an interview with NBC10. He goes by the nom de guerre, Abu Hamza al-Amriki, and has been identified by national security officials as one of the speakers in a May 2017 ISIS propaganda video. Al-Amriki is Arabic for "The American."
Dressed in fatigues and armed with an assault rifle, he implores "lone wolf" attacks on the United States while kneeling in front of rocket launchers.
After The Atlantic first reported last weekend that a New Jersey man named Nulfi Hoxha went to Syria in 2015 and became the soldier named Abu Hamza al-Amriki, NBC10 found his family in Margate. His mother, Ltefaji Hoxha, confirmed that her son is the man in the video.
"I am upset," his mother told NBC10 at her house in Margate on Wednesday. "No good. I'm very upset."
The family had at one time owned a pizza shop in Margate, and Zulfi Hoxha graduated from Atlantic City High School in 2010.
It's unclear who he was referring to when he used the word "we" in conversations with Cacia and others as a younger man, since his mother said Zulfi Hoxha was born in the United States.
Ltefaji Hoxha said she came to New Jersey from Albania many years ago.
The FBI was apparently a few months too late in tracking down Zulfi Hoxha, according to a former friend who grew up in Margate with the ISIS soldier.
The friend, who asked not to be identified, said the FBI asked him to wear a wire in 2015 and talk to the Hoxha family about their prodigal son. The FBI would neither confirm nor deny an investigation of Hoxha.
But at that time, the friend said, Zulfi Hoxha had already left the country. According to court documents in a federal terrorism case against another American ISIS sympathizer, David "Daoud" Wright, Zulfi Hoxha had left to go to Syria in April 2015.
In a story titled "A New American Leader Rises in ISIS," The Atlantic describes how Hoxha's reputed status as a senior commander "places him in an elite category of the group’s American members who have risen to some level of leadership."
The writers noted how most American wannabe-ISIS soldiers never make it to the Middle East. More than 50 Americans, the Atlantic reported, have been arrested in the last three years trying to go to Syria.
Some others are like David Wright have been busted for devising attacks or conspiring to recruit fellow Americans.
Wright was sentenced to 28 years in federal prison in December 2017 for plotting "to kill innocent Americans on behalf of ISIS," Massachusetts Acting United States Attorney William D. Weinreb said at the time.
In court filings during Wright's case are the first references to the New Jersey man turned ISIS leader.
Nulfi Hoxha hasn't reached out to his family in over a year, his mother told NBC10.
Ltefaji Hoxha said the last time he talked to her he said, "'Zulfi is good.'"
Echoing the supposed jokes Zulfi Hoxha exchanged with co-workers at Johnny's, his mother also said he became disillusioned a few years ago with a mosque in Atlantic City. He would say "he hate," his mother said, struggling with her English. She told him to stop going to the mosque.
Attempts to identify the mosque have not been successful.