I'm confused?

Rating: Null/10 (3 August 2005)

OK..first of all, I REALLY enjoyed this movie..just got finished watching it the 2nd time w/ my hubby. But I have a few questions, and I do not have time to read all the comments to see if there are answers because I have to work in the morning..so maybe someone can help me out here. the rest of this contains spoilers: So, Malcolm really did kill 6 people...in an apartment bldg, right? Was one of them his mother..because they kept showing a photo of a dead woman who could have been possibly his mother? I know they didn't go into detail about the people that were REALLY killed..but I was thinking that since the Larry character AND the child both had this hatred for prostitutes, and Malcolm's mother was a prostitute..that maybe somehow there was a connection? Also...why, after Edward finds the key next to the woman's bed, and they found the #7 key on her husband's body..why were they all of a sudden in a big hurry to flee the area? I didn't understand that part..did they all think they knew who the murderer was or something..because before that, the Ray Liotta character said they should all stay in the room. I'd appreciate any feedback on this..thanks!..(p.s. Ray Liotta rocks!)