Federal and local officials allege 65-year-old Earl Albert Moore planted a pipe bomb and propane tanks in the Southwest Plaza Mall in the south Denver suburbs last week. The explosives were found April 20 after a fire in a hallway at the mall's food court, but they didn't detonate.
The discovery - on the 12th anniversary of the Columbine shootings just two miles away from the school - initially raised concerns about whether it was connected to the school attack because they both occurred around the same time of day and because a pipe bomb and propane tanks were also found at Columbine, where teenage gunmen killed 12 students and a teacher. But authorities now say the bomb had nothing do with Columbine.
FBI agents have said they have found a motive, but they refused to reveal it Tuesday.
Police arrested Moore after a shopper spotted him having a cup of coffee in a Starbucks inside a King Soopers grocery store in Boulder. Authorities said he was unarmed and officers didn't have to draw their weapons.
Officials identified Moore as the suspect on Sunday after viewing surveillance video showing him in the mall and on a bus. The FBI then alerted its field offices covering all 50 states and Puerto Rico to be on the lookout for Moore, who was released from prison a week before the explosives were found.
It's unclear where Moore spent the past six days but FBI spokesman Dave Joly said he was homeless. He's due to appear in court Wednesday.
Kelli McGannon, a spokeswoman for the King Soopers supermarket chain, said the shopper who spotted Moore alerted a store manager and then dialed 911.
McGannon said a police officer inside the store began watching Moore, but it wasn't clear if the officer had identified Moore independently or was reacting to the 911 call. Moore was in the store for about an hour, McGannon said.
Moore left through a side door, possibly suspecting he was being watched, McGannon said. He was arrested outside by officers responding to the 911 call.
Police and store security searched the supermarket after Moore's arrest and said they didn't find anything suspicious.
Moore has an extensive criminal record and public records show he lived in Colorado at least part time from the mid-1980s to 2004.
Federal Bureau of Prisons records show that Moore was released from prison April 13 after serving time in a federal prison in Atlanta and Estill, S.C. Federal court record show that Moore pleaded guilty in May 2005 to robbing a bank in Crab Orchard, W.Va., of $2,546.
A Federal Bureau of Prisons spokesman Edmond Ross said Moore received a "good conduct" release from prison after serving six years of his sentence.
Colorado Bureau of Investigation records show several arrests for possession of dangerous drugs, theft, and possession of burglary tools dating to 1984. Court records show that an arrest warrant had been issued for Moore in September 2004, six months before the West Virginia bank robbery, for his failure to appear at a court hearing related to a burglary case.
Moore also served a year in Danbury, Conn., federal prison in 1983, according to Ross. In 1985, Moore pleaded guilty to unlawful escape from custody of the attorney general and possession of an unregistered firearm. Details of that case, including where he served his prison sentence, were not immediately available from the Federal Records Center in suburban Denver.
Moore has used at least seven aliases that include variations of the names Earl Albert Buchannan, Donald Charles Morelli and Gary Steele, according to state arrest records. In addition, the FBI said Moore also uses the alias John Lindzy.
Public records show the owners of an apartment complex in Denver had filed to evict Moore and a female relative in October 2004 for failure to pay rent, The Denver Post reported.
Two banks also filed claims saying he owed them a total of more than $11,000, Denver court records show.
Associated Press writers Catherine Tsai and Sheila V Kumar contributed to this report from Denver.