Stacy Fleming, 23, second from left, hugs her friend Pam Frakes Monday, July 23, 2012, at a make shift memorial that the public created across the street from the Century Theater where a mass shooting occurred last Friday killing 12 and injuring dozens of others in Aurora, Colo. (AP Photo/Barry Gutierrez)

Family members of some of the 12 people shot to death during a midnight movie showing in Colorado are speaking out about some behind-the-scenes events they say need to be aired publicly.

They have scheduled a news conference for late Tuesday morning.

A spokeswoman for the group declined to comment on what the families would talk about.

A gunman wearing body armor and a gas mask opened fire on July 20 in a packed theater in the Denver suburb of Aurora during a showing of a Batman movie.

In addition to the 12 killed, 58 were injured.

The 24-year-old suspect, James Eagan Holmes, faces charges of murder and attempted murder. He's being held without bail and hasn't entered a plea.

Defense lawyers have said Holmes is mentally ill.