Mourning the dead in Aurora

Worshipers in Colorado head to church Sunday near the Aurora movie theater where a dozen people were killed by a gunman at nearby movie theater.

The morning mass at Queen of Peace Catholic Church was dedicated to the victims of shooting rampage in the Denver suburb.

Twenty-four year old graduate school dropout James Holmes, 24, was arrested immediately after the fatal spree at the local multiplex.

On Saturday afternoon, the local coroner's officer released the names of the 12 people killed, including those of a six-year-old girl and a young man celebrating his 27th birthday.

Some are asking why it happened.

(SOUNDBITE) (English) ROSIE MELICHAR, CHURCH ATTENDEE, SAYING:

"I would like to know, what kind of materials has he been reading? What's in his house besides all those explosions. What was on his computer? What was he looking at? What kind of books? What kind of people did he associate with? Even though we should remember the victims, I still want to know what caused this to occur."

The mass shooting stunned the nation and evoked memories of the 1999 massacre at Columbine High School just miles away from Aurora where two students opened fire and killed 12 students and a teacher.

Deborah Lutterbeck, Reuters