Dark Knight Massacre Victims Hire Casey Anthony's Attorney

41-year-old Marcus Weaver -- whom James Holmes shot twice in the upper shoulder during the tragedy -- tells TMZ, "Over the past 30 days of agony, along with very careful thought and consideration, I have hired Attorney Jose Baez as my legal counsel."

TMZ broke the story ... Baez has already been hired by a woman named Shirley Wygal -- whose 32-year-old daughter was shot and killed by Holmes.

Now, Weaver says, "I felt that the night of the incident, that the security at the theatre was lacking from the time I entered. I want answers, we ALL want answers. And I know Attorney Baez will do what ever he can to help with the fullest extent of the law."

He adds, "Every day, early in the morning or at night, I have a movie in my head of what happened. I wake up every night with nightmares. I don't think it will ever go away."