A Little Farfetched...(spoiler )
There is so much going on in this movie that its really hard to determine the truth, but it makes it so much fun to draw up our own assumptions (like we're the detective trying to help solve the case)
For the most part I had the same ideas as everyone else but I also explored the idea that maybe the brother was involved somehow (possibly even with the neighbors) . Here's just a few reasons why I got that vibe but I'm not quit sure how it all connects...
-He was the last person to see her in the water and he just left her by herself
-It was emphasized that the two were extremely close. Almost seemed like a couple or even maybe he had an abnormal obsession
-He was the one adjusting the footage of the so-called ghost and the footage that ultimately gave him away was of him wandering in the area Alice died and he stated he was trying to avoid someone when the couple happen to get him on film
-when the neighbor was caught in his camera by his mom, it was coincidentally the footage matt was altering at that same moment. Not sure how matty didnt run into him.
-He had unexplained bruises for weeks that I believe were either self-inflicted or Alice seeking to warn/threaten him
-even though they did get along so well there was a collage of film showing them bickering and the last picture in the collage was also the last picture in the closing credits and was filmed by matty.
-Maybe he was involved with the sex tape. (either taking/setting up camera bc it never shows their face, or maybe it was his camera and he found the tape and made sure it was found to take any attention off himself.
-There was also a section of film showed with alice and matty acting a little flirty at the pool and then there's another section of film with that same day only she was now flirting with the neighbor
Sorry for the long explanation. I know these can prove either he was helping Alice or hurting her but I cant decide. Maybe you guys can add or rebut some of this so I can connect it better...I
I have another idea about Alice but I'll post it separately so not to overwhelm everyone. hahaha Thanks everyone!