CANYON, Texas (KVII) — The teenager accused of plotting a Fourth of July attack had "highly sensitive explosives" used by terrorists.

According to a court document obtained by ABC 7 News, the Department of Public Safety (DPS) found hexamine, hydrogen peroxide, and citric acid in the Canyon home of 18-year-old Kevin Alexander Hunt.

DPS said in the document that Hunt had the chemicals "with the intent to combine the components into an explosive weapon" known as HMTD.

The National Counterterrorism Center, Department of Homeland Security, and FBI said HMTD, which is "of interest to terrorists," is "generally easy to detonate and may be used in improvised detonators."

As ABC 7 News first reported Saturday, when we broke the story, DPS learned about the plot and placed a GPS tracker on his SUV.

According to a source, DPS noticed Hunt was repeatedly driving the route for the Fourth of July parade in Canyon.

They arrested him on July 2 at VFW Road and Tatum Schulte Lane, approaching his SUV with guns drawn.

According to a source, Hunt had traveled around Amarillo and Canyon trying to purchase an AR-15, but was unable to do so.

He then bought magazines for an AR-15, hoping to still get an assault rifle.

He also bought a bunch of ammo.

The day of the parade, area police were placed on alert in case Hunt was not acting alone.

DPS is expected to release information about the case this week.