I read both of them. I think they are both great stories with a O. Henry feel and a dark twist. The Stalker also kind of hints at the ending. Have reflected on both, I think it is because you subtly guide them (the audience) when you need to be less intrusive.
If you don’t mind, could you tell me what gave it away? I’ve tried to avoid any hint as to what the truth is, so I’d be interested to hear how you knew. Or is it just because you’re expecting a twist, so you were able to pre-empt it? Any suggestions on how to be more subtle would be appreciated, as this is the one twist ending that I’d really like to avoid people guessing halfway though the film. (EDIT: Just thought of something that could be pretty major… How about I take out the part at the very start of the interview where they actually mention the possibility of a false confession? The journalist then doesn’t mention it until the very end. That way, the audience wouldn’t even question whether the killer did it or not, it’d just be a writer interviewing a murderer. Think that could work?)
I think you hit it on the head. I might have Joseph start with
JOSEPH: "Hey, you're that reporter that tries to get inside a killer's head, aren't you?"
MARK: "The facts speak for themselves if you give them a voice. (beat) Do you hear voices?"
JOSEPH: "No! I'm not crazy!"
Mark pulls out a few crime scene photos and lays them out.
MARK: "So this is the work of a sane man? Murdering young girls? Why would anyone do this?"
This subtly twists the conversation. It suggests the journalist is cleverly trying to find out why and it leads the audience to gently 'side' with the journalist. I put Mark for simplicity here. As for the interview, keep it very open. "How long did you watch the Culverson girl coming home from school before you decided to take her?" This sounds innocent enough as an interview question but it implies a deeper knowledge. I'd throw in a 'red herring'.
MARK: "In researching your childhood, I noted that your sister lived with your mother after the divorce. How did you feel about that?"
JOSEPH: "I never really ..."
He studies Mark's face.
JOSEPH: " ... She was a bitch. She left me to take the beatings from my drunk old man."
It has nothing to do with it, in fact. But for the audience, groping to make sense of what they are watching, they will fancy all sorts of psychological depth. You stacked up teddy bears and origami frogs, but didn't make them relevant. The journalist suddenly seemed to know more than the 'killer' which kind of tipped it for me. To maintain the suspense you need to keep the killer one step ahead until the end.
JOSEPH: "Did they find my calling cards on these new victims?"
MARK: "Calling cards? The pictures?"
JOSEPH: "No, the teddy bears."
MARK: "My contacts in the police say they didn't release all the details to avoid copy cat killers."
He rustles through some papers.
MARK: "There's been a new murder like the ones you committed. Remarkably similar."
Now you've raised at your critical point that he might be innocent. But you persist just a bit.
As for being a real journalist, it will save you lots of headache. Hey, it works for Dexter to be a serial killer in the Police Dept. Also, before such an interview tons of credential checking would be done. A simple false pass would not work. So for continuity, I'd keep him a real journalist.
I’m really happy nobody has come along and said my writing’s terrible! Makes me feel at least slightly better about myself! Anybody fancy reading through The Stalker for me? I actually think it’s a little better than The Confession, plus it’d be easier to make, so, of the two, I’m leaning more towards producing that one first. Cheers!
I think you have a good writing style. However, do check your grammar for the verbs SIT, LIE, and LAY. (In "The Stalker" p.2 "... he is sat in his car" and p.1 " ... she is laid in bed ..."

rather "he sits" and "she lies"--try to avoid the whole progressive and passive tenses altogether.)
I liked The Stalker but again it becomes obvious quickly. Partly because she acts suspiciously and he does nothing too suspicious. You made a big deal of her grabbing the camera and then she drives off when the guy comes up. The house would have been safety. Her actions did not match to a young woman actively engaged in life. Similarly all he did was watch her--as might a detective hired to see if a wife is cheating. You might have her leave then have him look through her garbage.
I might make her more obsessive in the end. More of a Baby Jane like ending.
WOMAN: (to Man) Why did you sleep with "ACTRESS"? They loved each other?
Man is dead with a bullet.
WOMAN: She couldn't love Mark like I can. I will protect him.
And close with her pasting the clippings, which is a great ending. My only concern is if it was his assignment, the police department is going to swoop down on her. So he needs to be privately hired. That would also allow him to snoop around her garbage cans, maybe be "break into her house" without a search warrant and generally have film shots that make him look suspicious. Perhaps have him move something. So when she returns and reaches around, it's moved. She pauses and seems nervous.
The more guilty he looks and more innocent she looks, the more powerful the ending. So I might have her talk on the phone to someone and make a reason why she's not at work.
WOMAN: Oh, hey Joan. Yes. This is my week off to get caught up. ... No nothing much. I'll even get to catch up on my soaps. .... Oh stop! ... Sure, let's do lunch.
She hangs up and gets a second call. "Hello." Silence. "... Hello? ... Who is this? ..." Shakes her head and hangs up.
Now we have set up a situation where she has a reason to not be at work. She seems normal. He seems to be more creepy.
To add to it, you might have her find a box on her doorstep. She opens it and finds something in it. She angrily/disgustedly throws it inside. At first we think she is the target. Later you reveal it is something she gave to MARK that was returned.
I like how you do the unravel at the end. But rather than give an exposition, I'd just rely on creating strong visuals. The white box on her door step = a white box she leaves for Mark; phone call slam = Mark calling her (have a clock with the same time in both locations, visible but not blatant).
The only part which seemed disjoint was the blood on her hands when referring to his wife and kids. At first I thought it was the detective's. If she murdered them, this would have been a very different story than stalking.
Anyway, nice job on both stories.