The defense in the R. Kelly trial continued their assault against the prosecution’s case yesterday, calling to the stand witnesses that attempted to cast doubt on the prosecution’s key arguments. The defense called a private investigator who testified that Lisa Van Allen – the supposed third person in the threesome sex tape – and her fiancé attempted to extort money from Kelly by threatening to sign a $300,000 tell-all book deal. Kelly’s lawyers also attacked the prosecution’s argument that the man in the sex tape has a black mole on his back that identifies him as Kelly, calling to the stand a forensic video analyst who said the mole that appears on the video is actually just “an artifact of electronic noise.”