Complex sentence: Cornwell purchased 31 of Sickert's paintings and destroyed one or more of them searching for his DNA, and eventually she was able to scientifically prove that the Ripper's DNA and Sickert's belong to the same 1%-fraction of the entire population.
Split into simpler sentences: Cornwell purchased 31 of Sickert's paintings and destroyed one or more of them searching for his DNA. She said eventually she was able to scientifically prove that the Ripper's DNA and Sickert's belong to the same 1%-fraction of the entire population.