Taking advantage of a Maryland law that allowed DNA tests following felony arrests, police took a cheek swab of King's DNA which matched a sample from the 2003 Salisbury rape.

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Matthews was arrested after the sample was matched with a family member whose DNA had been collected for the national database.

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Mr Pitchfork was asked to provide a sample, and it matched the semen from both victims.

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Each sample from the earlier series was matched with the most similar one from the later series, and they were placed in identical cell cultures to see which would multiply the most.

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Soon after being contacted by Mr Ontko, French police were able to confirm that DNA traces found in the dormitory of the hostel in Pleine Fougeres and from a sample taken from Montes in Miami matched.

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