Complex sentence: The prosecution at trial had argued that the DNA must have belonged to one of Stone's friends; however, the lace proved to be missing and so the CCRC were not able to re-examine it using modern DNA techniques.
Split into simpler sentences: The prosecution at trial had argued that the DNA must have belonged to one of Stone's friends. The lace however proved to be missing and so the CCRC were not able to re-examine it using modern DNA techniques.