My older sister is fairly clairvoyant and has been for as long as I have known her. She has always been able to sense things before they happen (e.g. surprise deaths of friends, weird instances of luck etc.) and has told us long before they do.
She was living by an older hospital here in Las Vegas and was walking home from the bus stop after work late at night and had something following her. As she describes it, it was a dark hulking shape approximately the size of a large rottweiler, but it was hunched at the shoulder. It moved way too fast for a dog though often darting from bush to bush along the neighboring yards making a beeline towards her. As she walked along the street at this point hurrying towards her house it started to laugh maniacally and growl all at the same time. She said she noticed a smell of something rotten and sulfurish (rotten eggs). It followed her for the better part of a quarter mile, and was rattling the bushes next to her trying its best to get her to focus on it. She did her best to ignore it and run towards her house but it was way too fast. At one point it began to make sounds as if it were saying something to her all the while laughing maniacally. She finally froze in her tracks under a street lamp and yelled at it to go away and to stop following her. It stopped quizzically and began to grow slightly bigger and was growling again. At which point a neighbor came outside and was on his way to his car to go to work when he saw my sister stare down what seemed to him a very large and twisted dog and yell,"Do not follow me, you will find no victim here! Your words have no meaning and no power! Now go!" The neighbor told me that it looked like it tried one more time to approach her but turned quickly and shot through the street faster than anything he had ever seen. He said he noticed red eyes also but seemed to mention that after the third time I asked him to relate this story.
About a week later a boy in the neighborhood was picked up for slaughtering his younger brother with a large buck knife. According to the newspaper (wish I still had the article) he told the police that it was a demon that would come to his window every night and whisper for him to kill his brother. When asked the murdering sibling said it was like a hunched animal that would growl and laugh at the same time while suggesting he murder his family members.
TLDR: My sister possibly came across something that influenced a neighborhood kid to slaughter his little brother.