In a deleted scene from Keeping Up With the Kardashians, Kris Jenner told the story about how she thought she found a critical piece of evidence in the O.J. Simpson case. It was an honest mistake, but also a scary one to find. It happened when Nicole Brown Simpson's mother asked Jenner to retrieve the children's belongings from their rooms at Nicole's house:

So, I start looking around ... We get to Sydney’s room, and on the four-poster bed ... on two of the posters, there was a handprint, and it was red. I went, ‘I think this is blood,’ so I called Marcia Clark. I go, ‘Oh my God, I’m at Nicole's house, and I think I see blood.’ They had forensic scientists within 30 minutes after we got there, and they did this analysis. She goes, ‘I'm going to call you back as soon as I can.

Sources: E! News