Unsolved cases that still creep you out to this day

The Keddie Murders
>in 1981, three people were found murdered in Cabin 28 at Keddie near the Sierra Nevada mountains in California
>the victims were Glenna Sharp, known as Sue, her son John (age fifteen), and his friend, Dana Wingate (aged seventeen). As well Tina Sharp who went missing and later declared dead
>all three victims found in the cabin had been bound with electrical wire and medical tape
>victims had been bludgeoned with a claw hammer, and Sue and John had been stabbed repeatedly. John's throat had been cut. Dana Wingate was also manually strangled and bludgeoned with another weapon
>one of the knives discovered at the scene had been used so forcefully that the bladeform had bent approximately twenty-five degrees
>Tina Sharp was missing, presumably abducted from the scene
>her skull was found three years later 95 miles from the cabin, but the rest of her remains are undiscovered
>case remains unsolved

Apparently the three boys and the oldest daughter next door were found to be alive. The older daughter first discovered their bodies in Cabin 28 the next morning.