Who sent the threatening letters?

A mother was receiving a continuous stream of anonymous correspondence containing seriously threatening content relating to her children.  Once the document examination aspect had been completed, the FDS fingerprint examiners chemically processed the letters for latent fingerprints.  Full sets of elimination prints were taken from everyone known to have handled the documents which included the mother and her four children.  It was suspected that the ex-husband and his new girlfriend had been sending the material.

We observed a common pattern type in many of the developed latent fingerprints on certain parts of the envelopes and stamps.  These latent fingerprints were identified as belonging to one of the children.  Once the child was informed that his fingerprints were found in these areas and on all of the letters, he confessed.