Visible crew/equipment: When Mrs. Hess' TV is off, if you look closely you can see the camera filming the shot and its stand. (00:16:40)
Visible crew/equipment: Alex fixes the TV to show a camera picture. The next scene when two of the criminals pull up in the car next to a mirror, a crew member is blatantly visible in the reflection, if you look closely on the left hand side. (00:37:10)
Answer: It was Jernigan who thought there was a woman in the shower and he couldn't take the risk that if it was a woman, that she would eventually get out and see intruders in the house and call for the police. The only option open to Jernigan would be to kill her so there'd be no witnesses.
No it was Beaupre who thought there was a woman in the house.
I've seen the movie and I can confirm that it was Jernigan who opened the shower curtain because he thought a woman was in the shower.