CINCINNATI » Christopher Lee Cornell showed little direction in his life, spending hours playing video games in his bedroom in his parents’ apartment, rarely going out or working, and voicing distrust of the government and the media. But in recent weeks, his parents say, they noticed a change in him.

They thought it was a change for the better: The 20-year-old suburban Cincinnati man was helping his mother around the house, cooking meals, sitting with his parents to watch movies, and talking about having become a Muslim.

"He said, ‘I’m at peace with myself,’" his father, John Cornell, recalled Thursday — a day after his son was arrested in an FBI sting and charged with plotting to attack the U.S. Capitol with pipe bombs and guns and kill government officials.

The arrest came with U.S. counterterrorism authorities on high alert against homegrown extremists and "lone wolves" — disaffected or disturbed individuals who hold radical beliefs but have no direct connection to a terrorist organization.

The bearded, long-haired Cornell was taken into custody outside a gun range and store west of Cincinnati after, the FBI said, he bought two M-15 semi-automatic rifles and 600 rounds of ammunition as part of a plan to go to Washington.

The FBI said he had for months sent social media messages and posted video espousing support for Islamic State militants and for violent attacks by others.

It was unclear from court papers if he had made contact with any terrorist groups.

But in an instant message to an FBI informant, Cornell wrote that he had been in contact with people overseas and that he planned to go ahead with the attack even without specific authorization.

House Speaker John Boehner of Ohio said a controversial government surveillance program was responsible for alerting authorities to the plot. He mentioned FISA, or the Foreign Intelligence Surveillance Act, which gives the government authority to eavesdrop under certain conditions.

Cornell, using the online name of Raheel Mahrus Ubaydah, told the informant they should "wage jihad," authorities said in court papers. He allegedly wrote in an instant message that "we should meet up and make our own group in alliance with the Islamic State here and plan operations ourselves."

Cornell was jailed for a federal court appearance Friday in Cincinnati. A federal public defender listed as representing him did not immediately respond to messages.

His father called him "a mommy’s boy" taken in by a "snitch" who was trying to help himself.

In court papers, the FBI said the unidentified informant had been cooperating with authorities to obtain "favorable treatment" in an unrelated case, and that the informant made contact with Cornell last August after telling the FBI about the social media posts regarding the Islamic State.

Similar cases in recent years have led to accusations of entrapment. But the FBI has argued such stings are vital for averting deadly terror attacks, and juries have returned tough sentences.

One such case involved an undercover agent pretending to be a terrorist who provided a teenager with a phony car bomb, then watched him plant it in downtown Chicago. In another instance in Boston, a man was sentenced to 17 years in prison for plotting with undercover agents to fly remote-controlled planes packed with explosives into the Pentagon and U.S. Capitol.

At Oak Hills High School, principal John Stoddard said teachers were shocked at the 2012 graduate’s alleged involvement in the plot. Stoddard said Cornell was a typical student, and teachers remembered him as quiet but not overly so.

Cornell wrestled in school, and a case in the family living-room displayed wrestling trophies and awards. But his father said Cornell quit, partly because schoolmates teased him about being in close contact with other guys.

He had a girlfriend but found she was "just using him," his father said. He didn’t pay attention to the news because he thought it was all propaganda from "Jew-run" media, and he believed presidential elections were controlled by a secret society, the elder Cornell said.

Green Township Police Chief Bart West said Cornell disrupted a 9/11 remembrance ceremony in a park in 2013. He was carrying a sign that read "9/11 was an inside job," according to West.

He wasn’t arrested. West said Cornell was asked to stand off to the side, and then other people at the ceremony stood in front of him to block the sign from everyone else.

West said police went to the home when Cornell was a juvenile. His father said Thursday that they had a scuffle that resulted in Cornell spending a few days in juvenile detention.

The father said his son couldn’t really decide what he wanted to do and didn’t seem to have any long-term goals. He had gotten a seasonal job unloading trucks and stocking items for a store chain, and received his last check last week, the elder Cornell said.

His parents said they believed he was saving to buy a car.

"I’m in shock," his father said. His mother, Angel Carmen, added tearfully: "I feel like my heart has been ripped out."

Associated Press writers Jennifer Smola and Mitch Stacy in Columbus, Eric Tucker in Washington and Lisa Cornwell in Cincinnati contributed.