From CDAN. https://www.crazydaysandnights.net/2020/11/four-for-friday-tomb.html

The Tomb: For nearly a decade, the things that occurred at the tomb of this deceased A- list child star (Heather O'Rourke) actually resulted in her body being permanently moved to an unmarked grave in 2001. She was originally placed in an above-ground mausoleum (Westwood Memorial Park, Los Angeles), which is still marked with her name and at which people still leave flowers and teddy bears. The weird stuff began happening the day after her interment. A man was seen after sundown taking a bouquet of flowers from her grave, but he fled before he could be identified. In the summer of 1988 someone used red spray paint to write "ALL WORN OUT - RR" ("Rocky Road"*) (episode: "Moscow on the Boardwalk") across the marble face of her vault. The family was notified, it was photographed, and then over the course of five hours the vault was cleaned. The police were called, but they didn't think it was important. For whatever reason the photograph didn't develop properly. Sometime in the fall of 1988 another man (probably the same as before, but there is no way of knowing) was spotted kneeling in front of her tomb after dark. He also fled when spotted. On the anniversary of her death in 1989, her family (mom, dad, stepdad, sister, grandparents) gathered at the tomb to remember her. It was very somber, they held hands, the sister placed a little stuffed Dumbo in front of the grave. As they were about to leave a man approached them and said something which frightened the mother. Her dad and stepdad each took her by an arm and led her away, back over to their car. Then they left. The unidentified man stayed behind and picked up the little Dumbo that the sister left and stuffed it in his pocket before leaving. Now here's where things get really strange. There wasn't much activity around her grave for several years. Then, in about 1991, her body was exhumed. It was done in the dark, so no one would notice. Her body was returned to the tomb three days later. In 1992, her body was exhumed a second time. One of the police present was asked why they were exhuming her again. He said, "What do you mean, 'again'?" Turns out the first exhumation wasn't legal even though they had what looked like real police and really good paperwork. Why did they want with the body of a deceased 12 year old? Surely it would warrant an investigation, right? Nope. Anyway, the coroner's office kept her for about a week before she was brought back and we reinterred her. In 1994 somebody had smashed the face of her tomb, removed her body, cut some hair from her head, and (fortunately) placed her back in the crypt. A worker there saw the corpse and he said she looked remarkably well-preserved. He started to float the possibility that her body had actually been replaced with an exact replica. The police investigation went nowhere. In 1999 there was another vandalism of the tomb. It wasn't another smashing, but red spray paint had been used again to write "BK KILLED ME" (Bruce Kane- developer of Rocky Road). In the summer of 2001 her family had her body moved to an unmarked below ground grave.