When you have conversations and speeches, you need to start the dialogue with a capital letter. There are a number of times where you haven't done this. For example, "He continued, 'why were you folks in the alley?'" Also, you have a tendency to use run-on sentences, and these can be a little confusing. An example of this is, "'That's interesting,' seeing through Emily's reluctance to answer, 'well maybe it was looking for a better angle,' Porter waved his pencil at Gigi, 'after all how would the Auto-Cam know to protect your family?'" Here, I would start a new sentence with "Porter waved his pencil at Gigi" because that's not a dialogue tag. It is the start of a sentence.
I was temporarily confused at the beginning of this story. You have the paragraph explaining the background to Porter's mysterious cases, and then you show Porter speaking to a client. I wasn't sure if Porter was remembering this having happened earlier, or if he was now in the present tense having it happen. I would try to clarify that, if I were you.
You have some missed apostrophes. A few times, you have something like, "stores CCTV" when there should be an apostrophe before the S.
A more specific point. You end a paragraph like this, "couldn't quite put together;" It should be a period not a semicolon.

"Harry, was Farmer Mike's favorite horse." - You don't need the full stop after "Harry" because he isn't being addressed.
"Harry was very special , not ..." - The comma needs to be backspaced.
"Carlie wanted to be like Harry and fly. she ..." - It should be a capital S.
"Georgette, provided very special milk ..." - you don't need the comma after "Georgette."
"that was her job!." - You don't need the full stop in addition to the exclamation mark.

"He couldn’t tell if it was a soda bottle or a beer battle but it didn’t matter. " - There should be a comma before "but."
"They’re all heirs to the deceased and apparently there were stipulations." - There should be a comma before "and."
"There was a threatening message left just after the murder and another last night." - There should be a comma before "and."
" ...trying to cover up their guilt by pin the murder on a ghost." - It should be "pinning."
" ...there’s no other way off the property as there are the inn’s two boats are unusable." - This doesn't make sense, but I'm not entirely sure what you meant to say.
"He listened to the other line ring until it was picked." - It should be "picked up."

" ...Derice was an honest and well-intentioned boyfriend for their daughter and they got engaged." - There should be a comma before "they got engaged."
"It was a nice compliment to Derice’s jerk ..." - It should be complement with an "e." With an i it means saying something nice about someone.
"Junior handed the mayor back his card and the mayor left." - There should be a comma after "card."
"The mayor took his place behind the podium and one of his staff handed him a card." - You need a comma after "podium."
"All the locals where surprised." - It should be "were" not "where."