CENTRAL ISLIP, N.Y. » A suburban New York man who plotted to join a Muslim militant group faces up to 25 years in prison when he is sentenced Monday in a Long Island courtroom.

Marcos Alonso Zea, 26, of Brentwood, pleaded guilty in September to attempting to provide material support to al-Qaida in the Arabian Peninsula, also known as Ansar al-Sharia, and obstruction of justice.

Federal prosecutors say the 26-year-old Brentwood, Long Island, man flew to London on his way to Yemen in January 2012. He was rejected by customs officials in London and returned to the United States.

Once home, prosecutors say, Zea continued participating in the conspiracy.

They say he gave money to and instructed co-conspirator Justin Kaliebe, also of Long Island, on how to evade electronic surveillance by law enforcement as he discussed Kaliebe’s plans to wage jihad.

Zea, who worked as a clerk at a home improvement store, was inspired by terrorist propaganda, according to the FBI.

Defense attorney Marc Bogotin has said in court papers that his client never committed any violent acts that would require him to receive the maximum penalty.

Among Islamic extremist materials found on Zea’s computer were issues of an al-Qaida publication that promotes violent jihad, authorities said. The publication contained articles such as "Which is Better: Martyrdom or Victory?" ”Why did I choose al Qaida?" and "What to Expect in Jihad?"

Investigators said they also found an al-Qaida-produced video depicting detonation of an explosive device on a vehicle carrying Western military personnel.

After learning he was under investigation, Zea directed an associate to erase a hard drive on his home computer and gave an associate two more hard drives to destroy, though investigators recovered them anyway, authorities said.

Kaliebe, who was arrested in January 2013 as he tried to board a plane in New York to go to Yemen, has pleaded guilty to attempting to provide support to terrorists and attempting to provide material support. He faces a sentencing hearing next month.