The Colorado massacre suspect

James Holmes, Aurora theater shooting suspect, sits in the courtroom during his arraignment in Centennial, Colo., March 12, 2013. Judge William Blair Sylvester entered a not guilty plea on behalf of Holmes on Tuesday after the former graduate student's defense team said he was not ready to enter one.

James Holmes sits with defense attorney Tamara Brady during his arraignment in district court in Centennial, Colo., March 12, 2013.

The parents of James Holmes, Robert and Arlene Holmes, arrive at district court for the arraignment of their son in Centennial, Colo., on Tuesday, March 12, 2013.

This photo released on Sept. 20, 2012, by the Arapahoe County Sheriff's Office shows James Holmes. Holmes is being held on charges related to the shooting at an Aurora, Colo., theater on July 20 that killed 12 people and wounded 52.

James Holmes, in a recent courtroom sketch

The booking mug for James Eagan Holmes released by the Arapahoe County Sheriff's Office in Centennial, Colorado. The picture was taken hours after a shooting massacre at an Aurora, Colo. movie theater that killed 12 and injured 58 people on July 20, 2012.

Holmes is seen at left in his first court appearance (with defense attorney Tamara Brady) at the Arapahoe County District Court in Centennial, Colo., Monday, July 23, 2012.

Wearing orange-red hair and looking at times emotional and at other times bleary-eyed, Holmes sat in a maroon jailhouse jumpsuit as Chief Judge William Sylvester advised him of the case.

Authorities disclosed that Holmes is refusing to cooperate and that it could take months to learn what prompted the mass shooting.

Colorado mass shooting suspect James Holmes appears in court, July 23, 2012. At right is attorney Tamara Brady, from the state public defender's office.

James E. Holmes appears in Arapahoe County District Court, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting last Friday in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others.

Law enforcement sources have confirmed to CBS News that this photo, taken from the explicit dating site AdultFriendFinder.com, is of Aurora shooting suspect James Holmes. Holmes had apparently been a member of the site since July 5, 2012 and used the phrase "Will you visit me in prison?" in his profile.

There has been no clear motive yet for the alleged actions by the 24-year-old. This photo was provided by the University of Colorado Denver

Holmes attended high school in the northern suburbs of San Diego. He participated in sports but was described by one person who knew him back then as intensely shy.

In high school, Holmes won a competitive position at a rigorous science boot camp and an internship in neurobiology at the prestigious Salk Institute, a non-profit, scientific research institute located in La Jolla, California. He is seen here at the facility in the summer after graduating high school in 2006.

In high school, Holmes won a competitive position at a rigorous science boot camp and an internship in neurobiology at the prestigious Salk Institute, a non-profit, scientific research institute located in La Jolla, California. He is seen here at the facility in the summer after graduating high school in 2006.

Holmes seen in a yearbook photo from Westview High School in San Diego. He played on soccer and cross country teams.

James Holmes is pictured with the Junior Varsity soccer team of Westview High in San Diego in either 2003 or 2004. — CBS News

Holmes is pictured with the Junior Varsity soccer team of Westview High in San Diego in either 2003 or 2004. He is no. 16 in back row.

Holmes is pictured in the 2003 Westview High School yearbook with the cross-country team.

Holmes, center, pictured in San Diego's Westview High 2005 yearbook when he was a junior.