Now, for the first time the public is hearing Shareef in his own words explain why a young man born and raised in America wanted to become a terrorist.
Shareef was a teenager living in Rockford when he converted to Islam. His mother has said she grew concerned about her son after he took trips to Detroit and Arizona, then grew distant as he became more radicalized.
The FBI says he was a young man who was working at a video game store by day while plotting to commit acts of terrorism in his off hours.
"You are the enemies of Islam, for the sake of Allah we are coming for you," Shareef says in a tape that looks like it could have been shot somewhere in the Middle East. In fact, the camera was 90 miles from Chicago in a Rockford home where the 22-year-old and a friend each made several videos declaring their desire for destruction.
"We will target you in your homes. We will target you in your businesses. We will target you in your synagogues and your churches. We do not fear you Kafirs. I swear by Allah I am ready to give my life right now for the cause," the tape says.
Days later, FBI agents arrested Shareef and charged him with swapping stereo speakers for what he thought were four live grenades and a handgun. Shareef's friend was actually an FBI informant who recorded Shareef plotting to detonate the grenades at Rockford's Cherry Vale mall during the height of the Christmas shopping season.
A born and bred American intent on killing his fellow countrymen. The type of person, Homeland Security says, is being recruited by foreign-born terrorists.
"Among these groups we are also seeing an increased emphasis on recruiting Americans and Westerners to carry out attacks," said U.S. Homeland Security Secretary Janet Napolitano last week.
"I would say it's a higher threat, a more likely scenario than an al-Qaeda inspired attack," said Robert Grant, FBI Chicago special agent in charge.
The FBI and others have been working to understand how an American like Shareef can be radicalized without ever leaving the country.
"There is a lot of people attempting to determine how fast a person can go from non-threat to threat and it's gotten very short, in some cases, amazingly short. It manifests itself in a matter of months as opposed to years," said Grant.
For his part, Shareef said in a series of letters to me signed with the peace symbol that he just happened to know the wrong people. Now in court filings he contends he was entrapped by his friend the FBI informant and the martyrdom tapes he made are little more than "boasting and bragging."
Attorney Tom Durkin has represented accused terrorists housed at Guantanamo Bay. He argues people like Shareef - and the young man charged with plotting to set of a bomb outside Wrigley Field - are the latest examples of law enforcement casting a wide net.
"Once you start declaring a war on terror like you do a war on drugs you get into activities that become very questionable from a civil liberties standpoint," said Durkin.
Shareef is serving a 35-year-prison term in downstate Illinois. He said he was willing and anxious to talk with ABC7 about his case. The Federal Bureau of Prisons said no deeming an interview a potential security threat.