This event happened when I was maybe three years old.
My mom was cleaning around the house, when I came out of my room and asked her to come to the bathroom with me, because I had to potty and "there's a man in there." So she went with me, and she couldn't see anyone, but she asked me to describe the man. I told her the man was a policeman. She asked me what color his uniform was, because she knew the colors worn by the different law enforcement agencies--Sheriff's Department, local police, and Highway Patrol. (Before I was born, my mother had been a dispatcher and deputy for the Sheriff's Department where we lived in northern California.) I said the man's uniform was tan, which meant Highway Patrol.
As we left the bathroom I pointed into my bedroom and said, "There's another one in there." I described how the men had been "shooted with a shoot-gun," one in the elbow and stomach, one in the knee (as well as other places--I don't remember exactly where, unfortunately). From the fact that two murdered CHP officers appeared to be hanging around in her house, my mom knew exactly who they had to have been--after all, she didn't know very many people who had been murdered! (I'm not writing their names because I don't know if there could be an legal fallout from doing so--I can't think why there would be, but just to be on the safe side...)
Some time passed, and my mom told this story to a friend of hers, who still worked for the Sheriff's Department. The fact that one officer had been shot in the elbow was one of the details that was withheld from the public as the cops investigated the crime. Even my mother hadn't known about that, but because of that she was able to confirm her guess about the the identities of the dead officers.
On December 22, 1978 the two officers, one of them a friend of my mother's, had made a vehicle stop on a stolen car. The driver somehow managed to get control of their weapons, shot one in the knee and one in the elbow, disabling them, and killed both with their own service revolvers. The officers were not expecting a fight and were caught off guard, and theirs was the only CHP car in the county that night, due to state-mandated cutbacks in nighttime patrols. At the time I saw the ghosts, the case would have been just going to trial.