(CNN) -

Here is some background information about the July 20, 2012, movie theater shooting in Aurora, Colorado. Twelve people were killed and 58 others were injured. Suspect James Holmes has been charged with 152 counts and has pleaded not guilty by reason of insanity.

Fatalities: (12 total) Jonathan T. Blunk, 26 Alexander J. Boik, 18 Air Force Staff Sgt Jesse E. Childress, 29 Gordon W. Cowden, 51 Jessica Ghawi, 24 Petty Officer 3rd Class John Thomas Larimer, 27 Matthew R. McQuinn, 27 Micayla C. Medek, 23 Veronica Moser-Sullivan, 6 Alex M. Sullivan, 27 Alexander C. Teves, 24 Rebecca Ann Wingo, 32

James E. Holmes: Birth date: December 13, 1987

Birth place: San Diego, California

Birth name: James Eagan Holmes

Father: Robert Holmes, a scientist

Mother: Arlene Holmes

Education: University of California, Riverside, B.S. in neuroscience, 2010 (graduated with highest honors) University of Colorado Anschultz Medical Campus, enrolled in 2011 as a doctoral candidate in its neuroscience program. Withdrew in June 2012.

Police say he bought the guns used in the incident legally at two sporting goods stores --- Bass Pro Shops and Gander Mountain --- and purchased more than 6,000 rounds of ammunition online.

Timeline: July 7, 2012 - James Holmes purchases a ticket, through an online ticketing agent, for the July 19 midnight showing of "The Dark Knight Rises" at the Century Aurora 16 Multiplex Theater, in Aurora, Colorado.

July 19, 2012 - Holmes attends the midnight showing of "The Dark Night Rises" at the Century Aurora 16 Multiplex Theater, in Aurora, Colorado. Holmes enters Theater #9 but soon exits through a rear door on the right side of the screen, leading to a parking lot. He leaves the door propped open and returns through it, according to a law enforcement source involved in the investigation.

July 20, 2012 - Eighteen minutes into the movie, shortly after midnight, a gunman opens fire into the audience.

The gunman is "dressed head-to-toe in protective gear"- a ballistic helmet, protective gear for his legs, throat and groin, black gloves and a gas mask. He props open the door, before throwing two tear gas canisters into the theater. After both canisters explode, witnesses say he started shooting, first at the ceiling and then at the crowd. Police say he used an AR-15 rifle, a 12-gauge shotgun and at least one of two .40-caliber handguns police recovered at the scene.

Twelve people are killed and 58 are wounded.

Holmes surrenders to police outside the theater within seven minutes of the first 911 calls, according to Aurora Police Chief Daniel Oates.

Five buildings, including Holmes' apartment building at 1690 Paris St., are evacuated after the suspect makes a statement to police about explosives in his unit. According to police, his apartment has been booby trapped with a tripwire at the front door that would have touched off an array of explosives and flammable liquids.

July 21, 2012 - Investigators disarm all the makeshift bombs in Holmes' apartment, using a "controlled detonation" to disable a second triggering device. The explosives removed include more than 30 homemade grenades and 10 gallons of gasoline.

July 23, 2012 - James Holmes makes his first court appearance. He is ordered to be held without bond.

July 25, 2012 - Authorities discover a package in a University of Colorado-Denver mail room apparently sent by Holmes.

July 30, 2012 - Holmes is charged with 142 counts including first-degree murder. Among the charges are 116 counts of attempted murder, one count of felony possession of explosive devices, and one sentence enhancer.

August 1, 2012 - Denver station KMGH reports Holmes' psychiatrist, Lynne Fenton of the University of Colorado, told colleagues in June that he could be potentially dangerous to others, but before any action could be taken Holmes began the process of dropping out of the university.

September 20, 2012 - Holmes appears in court to hear the State's motion adding ten additional counts of attempted murder. He is now charged with 152 felonies.

October 11, 2012 - A Colorado judge approves 14 more attempted murder charges against Holmes, bringing the total to 152 charges, including murder and weapons offenses.

October 26, 2012 - The State files a motion to bring additional attempted murder charges against Holmes. He faces a total of 166 charges.

November 16, 2012 - It is announced that the Aurora Victim Relief Fund will distribute donations to families of those killed and some victims wounded in the shooting.