A possible concise summary is:
This is a transcript of a YouTube video by Mr. Ballen, who tells stories about the strange, dark and mysterious. He narrates the case of Mike Riemer and Diana Robertson, a couple who went missing in 1985 after camping in a forest near the Nisqually River in Washington. Their two-year-old daughter Crystal was found alone and confused at a Kmart parking lot, saying only "mommy's in the trees". Diana's body was later found stabbed and strangled with a tube sock, while Mike was suspected of being the killer and a fugitive. However, 25 years later, Mike's skull and jawbone were discovered in the same forest, suggesting he was also a victim of a serial killer who had attacked other couples in the area. The only witness to the crimes was Crystal, who could not provide any useful details. The video ends with Mr. Ballen asking his viewers to like, subscribe and follow him on social media, and to submit their story suggestions to his subreddit.
Here are some possible facts extracted from the text:
1. Michael Riemer and Diana Robertson were a couple who had a two-year-old daughter named Crystal.
2. Michael was a roofer and a trapper who knew the forest near the Nisqually river very well.
3. Diana had filed a restraining order against Michael in October 1985 after he had kicked in the door and thrown her to the ground.
4. In December 1985, they reconciled and went camping in the same forest where Michael had his traps, hoping to find a Christmas tree.
5. Crystal was found alone and confused in a Kmart parking lot 20 miles away from the forest, saying "mommy's in the trees".
6. Diana's body was found stabbed 17 times and with a tube sock around her neck in the forest, near Michael's red pickup truck.
7. A note that said "I love you Diana" was found on the dashboard of the truck, but the FBI could not confirm it was Michael's handwriting.
8. Michael's skull and jawbone were found in the same forest in 2011, indicating he had died around the same time as Diana.
9. The police suspected that Michael was also responsible for the murders of Stephen Harkins and Ruth Cooper, another couple who were killed in the same forest four months earlier, with Ruth also having a tube sock around her neck.
10. The police later realized that Michael was not the killer, but rather a victim of a serial killer who had killed at least eight other couples in and around the forest.