A Colorado man was arrested by the Department of Justice (DOJ) after he allegedly attempted to board a plane to join the Islamic State (ISIS). Humzah Mashkoor, 18, of Westminster, Colorado, was arrested on Monday at the Denver International Airport attempting to board a plane to the Middle East, according to the DOJ. He reportedly planned to travel to the United Arab Emirates (UAE) where he hoped to stay until he could obtain a visa and travel to either Afghanistan or Syria and serve as a fighter for ISIS. Mashkoor was charged with attempting to provide material support to a designated foreign terrorist organization. https://twitter.com/DOJNatSec/status/1737242219675787484 Law enforcement officials began investigating Mashkoor after he began posting support for ISIS on social media around November 2021, according to court documents, Denver7 reported. Mashkoor allegedly also used his social media to get into contact with other supporters of ISIS, according to court documents. In September 2022, Mashkoor began contacting several FBI agents who had been undercover supporters of ISIS and used fake names and code phrases when speaking to them, according to court documents. During his conversations with the undercover FBI agents, Mashkoor reportedly informed them that he had been born in the United States, but traveled to Afghanistan before his family was "forced to leave" the country. Mashkoor went on to express his interest in joining ISIS, gave them money and assisted them in recruiting other ISIS supporters, even though he wasn't 18 yet, according to court documents. In June 2023, Mashkoor said he wished to find a wife, a job and finish his education, but was worried about leaving her if he became "martyred." However, in July, he told one of the undercover agents that he no longer wished to finish his education and intended to join ISIS. Mashkoor's family reportedly did not have knowledge of his plans to travel abroad, and he bought a one-way ticket from Denver to the UAE around Nov. 25 for Dec. 11, according to court documents. After coming down with COVID-19, Mashkoor was reportedly forced to change his flight departure for Dec. 18. The day Mashkoor was set to travel, he and a relative who had a return ticket, arrived at the airport around 8:33 a.m., checked their bags, and went to the TSA screening area where he was taken into custody, according to court documents. During this time, FBI officials reportedly conducted a search of Mashkoor's home after obtaining a search warrant. After searching the home, officials allegedly found journal entries of what appeared to be the ISIS flag and a letter explaining his decision to join the terrorist organization. Some of the journal entries reportedly say, "I fell in love with their (ISIS) steadfastness in the face of such animosity," and "From then on I decided I wanted to be like them. Leaving behind the hypocritical life of humiliation to migrate to the lands of jihad." "I will never forget all that you've done for me and I'm sorry for how I treated you. Goodbye," Mashkoor reportedly wrote when ending his journal entry, according to court documents.