A North Texas man is in federal custody, accused of providing bomb components and money to help what he believed was ISIS.

Instead, authorities say the man was unknowingly communicating with undercover law enforcement officers.

The suspect, 21-year-old John Garza Jr., was born in Arlington and lives with his family in Midlothian, according to his father, John Garza Sr., who spoke with NBC 5.

Garza Sr. said he works with his son at a restoration business and was shocked to learn of the allegations.

According to a federal criminal complaint, an undercover New York Police Department employee began messaging an Instagram account in mid-October. The account had followed several pro-ISIS profiles and commented on a post promoting the Islamic State.

The complaint said the undercover employee portrayed themself as an ISIS fighter in Iraq and developed a rapport with the account holder, who was later identified as Garza Jr.

Throughout the complaint, Garza is described as sharing support for the Islamic State, including ISIS press releases, a video depicting a suicide bombing and a photo of what he described as his computer setup inside his Midlothian home. The image displayed the Ajnad logo, an ISIS media outlet.

In November and December, the U.S. Department of Justice says Garza sent about $40 in Bitcoin to the undercover officer. After receiving a photo of three guns, which the officer claimed had been purchased with the money, Garza reportedly said he would send more.

The two-and-a-half-month investigation culminated in a meeting at a Dallas park on Dec. 22, according to the complaint. Investigators say Garza met with another undercover officer, whom he believed to be an ISIS “brother,” and handed over bomb-making materials. He also sent a video explaining how to build a device.

Garza was arrested roughly 30 minutes later at his home in Midlothian.

The DOJ says a search of the home uncovered what Garza had described as a detonator.

“I wouldn’t want to be the person charged. It looks like a pretty strong case,” said retired FBI Special Agent Edward Shaw, who commended the multi-agency investigation.

Garza’s father told NBC 5 the allegations came as a complete shock. He said his son has never expressed pro-ISIS ideations and was diagnosed with a neurological disorder. He believes his son was preyed upon and pressured into doing things he would not have done otherwise.

He said he is now mounting a fight for his son’s freedom.

Garza made his first court appearance on Dec. 23. Another hearing is scheduled for Dec. 30.

If convicted, Garza faces up to 20 years in federal prison.