Weiler's family says the 23-year-old left the Chicago area a few years ago to join a religious group. Yet, it was religion that apparently was the motive behind the alleged bomb plot.
On a rambling Facebook entry posted a couple weeks ago, Weiler used the words "hypocrisy," "murder" and "deceit" when talking about the leaders of the Catholic Church.
Weiler checked into this Oklahoma motel over two weeks ago. Police say he spent his time plotting to blow up dozens of churches.
The Elk Grove native was tracked down by police after bomb making equipment was found in the motel dumpster. Inside Weiler's motel room, police discovered about 50 beer bottles that were made into Molotov cocktails.
"I had no idea about it, but i knew he was having tons of problems, best we could," said Matthew Weiler, the suspect's brother.
Weiler's family said he has been having problems with mental illness for years. Matthew Weiler and his cousin Johnny Meyers say it was only a matter of time before Greg Weiler was going to be in serious trouble. They are relieved he is in custody.
"We are hoping that through being caught and all this, he will get hospitalized, get better," Meyers said.
"He is in the safest spot he can be right now and we are just relieved he didn't hurt anyone," said Greg Weiler.
Weiler's family has not spoken with Greg since he left Elk Grove Village for Missouri three years ago.
Matthew Weiler says his brother went there to join a religious organization.
According to a September 25 lengthy entry posted on his Facebook page, Greg Weiler blasts religion, specifically the Catholic Church.
Written from his motel room, Weiler ends his entry by writing, "I have not opened a bible in a while and I haven't stepped foot into a church building in quite some time and though I may be very lonely right now, I am hoping that someone, and maybe someday in the future, someone will take notice.''
While Weiler sits in jail accused of a deadly terrorist plot, his family says he is not a monster
"We just want people to know he is a kind hearted person and without proper medication, he can't make clear judgments and proper decisions," Meyers said.
Weiler's family assumes he was off his medication, although they do not know for sure.
Weiler has a very troubled past. After both of his parents committed suicide, Weiler was taken in by his aunt and uncle. They had Weiler hospitalized several times for mental illness as well as alcohol and drug addiction.
Police believe he acted alone.