The son of a Boston police captain was sentenced this week to 20 years behind bars for plotting a series of terror attacks that federal prosecutors said were inspired by ISIS.

Alexander Ciccolo was arrested in July 2015 after his father, a veteran police officer, tipped off authorities about his son’s interest in the terror group.

NORTHERN BERKSHIRE DISTRICT COURT VIA ASSOCIATED PRESS U.S. District Court Judge Mark Mastroianni sentenced Alexander Ciccolo, now 26, on Wednesday to two decades in prison and a lifetime of supervised release for his crimes.

Undercover agents and witnesses cooperating with the FBI began corresponding with Ciccolo, who revealed his plans to attack several crowded places in New Mexico, including a university, a police station and a “gay-friendly bar,” reported the Boston Globe.

Ciccolo, now 26, was eventually taken into custody following a sting operation in which he requested and then accepted several firearms from an FBI witness — a criminal offense due to an earlier conviction. When officers searched Ciccolo’s apartment, they found several partially-made Molotov cocktails filled with “shredded Styrofoam and motor oil,” per NBC News. Prosecutors later said this was a tactic used to make the devices “stick to people’s skin and make it harder to put the fire out.”

Two machetes, a long, curved knife and a pressure cooker similar to the one used in the Boston Marathon bombings were also discovered in Ciccolo’s home. Described by prosecutors as a “committed soldier” of the Islamic State, Ciccolo was said to have been inspired by the marathon bombers, NPR reported.

In May, Ciccolo pleaded guilty to providing material support to a foreign terrorist organization, attempting to use weapons of mass destruction, illegally possessing firearms and assaulting a nurse during a jail intake process.

On Wednesday, U.S. District Court Judge Mark Mastroianni in Springfield, Massachusetts sentenced Ciccolo to two decades in prison and a lifetime of supervised release for his crimes.

“Alexander Ciccolo planned to kill innocent civilians in the United States on ISIS’s behalf,” Andrew Lelling, the U.S. attorney for Massachusetts, said in a statement following the sentencing. “Even though he was born and spent most of his life in Massachusetts, Ciccolo decided to turn against his country and plotted to attack his fellow Americans.”

“Thanks to the tireless investigation and swift response of our law enforcement partners, Ciccolo was unable to carry out his violent plan,” Lelling continued. “The sentence handed down today reflects our commitment to bringing all those whose allegiance lies with terrorists to justice.”

Federal prosecutors also acknowledged the critical role that Ciccolo’s father, Robert Ciccolo, played in securing Alexander’s arrest.

“The government recognizes that Captain Ciccolo’s decision to come forward was heartbreaking,” federal prosecutors said in a conviction memorandum filed last week, adding that he “likely saved the lives of numerous innocent people.”

Ciccolo’s father, who’s served 35 years in law enforcement and reportedly oversaw more than two dozen officers during the Boston Marathon attack, has not spoken publicly about his son’s arrest or conviction, according to the AP. In court documents, however, Ciccolo’s attorneys quoted his father as saying he did not believe his son was capable of actually following through on the planned attacks.