A good friend of mine was a homicide detective in Florida for a long time. He told me a story, one time when I was staying over there for a few months on business.
It was a case he'd just picked up. Family vacation from ohio, missing for a few days. Mum, dad, two daughters (fifteen and seventeen) The manager of the small hotel they were staying at said they had gone out for the day and not come back. That was it for a week, until dad's body washed up in the swamps and was found by a couple of froggers one evening. GSW to the face - Looked like rifle, probably a .308, based on the entry and exit wounds, and the couple of fragments left in the skull. Two to the brain, maybe from two feet away according to the scene techs and the ME. The case was turfed over to my brother. The body didn't show much - It's time in the marshes had ruined any time of death calcs, lividity and rigor was fucked, liver temps completely out of the question. Prints, likewise. Wrists and ankles showed signs of ligatures or restraints, and there was extensive bruising. Guy'd been tied and beat up real good. No prints, no fibres, no trace. Real clean, cleanest he'd seen for a while.
That was it until the video came. It was dropped off at the station, addressed to him. Nobody saw who brought it in. He played it in his office, first. Puked in the wastepaper basket. Called his partner and his lieutenant into the room and rewound to the start.
It was bad, to say the least. It filled in a lot of the blanks, and gave them somewhere to start - Found out where they were last seen and found out details from a few witnesses.
The family had been out eating lunch at a small restaurant when they saw a man driving one of those airboats on the open areas. He'd left it by the shore, and one of the girls asked their dad if they could try and find one. The owner had been having a BLT nearby and overheard. He was a friendly guy, no more then maybe twenty. White but tanned, according to the waitresses. Tipped well, wore faded jeans and a black t-shirt. Short blonde hair and steel-toed boots. The father was hesitant at first, but after a short conversation he didn't see the harm, and paid the man fifty dollars for a real florida airboat ride.
They were deep in the swamps when he made his move. Nobody knows how he got them where he got them, but nobody saw them after they left the diner. My colleague theorised that maybe he faked engine trouble, or stopped to refuel the boat at the small shack depicted from the inside on the video. it doesn't really matter, what does matter is that the video opens with the family bound with baling wire while the cameraman stands over them, wearing a black balaclava and holding a sawn-off rifle. He gave the father a good hiding with the stock and his boots, then shoved him into another room. The mother was too old for her tastes, she was beaten unconcious and locked in an ice chest.
The girls, though. They were repeatedly raped and mutilated. Forced to eat each other out, suck each other's tits and make out. One would have her throat fucked while the other rimmed her at gunpoint. From the timestamp on the video (which stopped and started now and then), this went on for about a week. End of the week, he took the girls back out onto the airboat and drove out to a deep spot - He'd been there before, we assumed, becuase it was well known to be the deepest spot around. Local's called it the Devil's Keep, must have been a meterorite crater or something from way back. The girls were bound again by this point. Mom and dad were long gone. He tied a cinderblock to each of their ankles and pushed them in. It was light enough so they didn't sink instantly, but heavy enough that they couldn't stay afloat for more then about fifteen minutes. He sat there, masturbating and drinking beer as he watched them drown. Then the video ends.
They never caught him. They sent divers down into the Keep for the bodies, found all four, but never recovered any usable evidence. My mate retired shortly after that. He couldn't handle that guy still being out there. And the look in the girl's eyes never left his mind. it was probably the last thing he thought about when he shot himself, six months later. It was a rage that burned deep within him, charred his soul from the inside out like a mine fire.
personally, I was just pissed that my beer got warm when I was driving the daughters back out to the keep.