Colorado Springs Police Department
Dear was taken into custody after police entered the building following an hours-long standoff.
Police have not yet revealed a motive for the 57-year-old's alleged shooting rampage that left three people dead and injured nine bystanders.
Dispatchers say the alleged gunman was wearing a long coat and a hat commonly worn by hunters, the Colorado Springs Gazette reports.
Reuters / Rick Wilking
Dear was charged in Colleton, South Carolina, with two counts of cruelty to animals in 2002, but was found not guilty in a bench trial.
He was also hit with "peeping Tom" and eavesdropping charges in 2002 in Colleton County. Roberts and her husband reported that Dear, their neighbor at the time of the incident, "had been making unwanted advancements to the victim [Roberts]."
"Memorial day weekend last year, 2001, was the first time that the Roberts noticed Mr. Dear in the bushes by their house," a report of the incident reads.
A restraining order was also filed against Dear by Lynn Roberts in 2002. No judgment was entered in that case.
The "peeping Tom" and restraining order charges were later dismissed.
Dear was also involved in at least two altercations that never reached the court system. The Daily Beast obtained police records that show in 1997 his wife, Pam, called police after Dear "took her keys from her and locked her out of their residence."
When Pam attempted to enter their shared home through a window, he "hit her and pushed her out the window," the report reads.
Pam "wanted something on record of this incident occurring and police took photos of "apparent bruises" on her body, The Daily Beast reports.
In September 2004, a neighbor named Douglas Moore reported to police that Dear had threatened him. Dear "told him that he was going to do bodily harm to him because the suspect thought the victim pushed his motorcycle over on the ground," records obtained by The Daily Beast reveal.
No further details have been released at this time.