According to the analysis of the inks and handwriting who should be a person of interest in the investigation

The answer is "John Huddleston".

The examination of inks in paper shows an imperative territory in forensic science, since it can be utilized to recognize conceivable adulterations and changes in an archive. However, the vast majority of the instrumental strategies proposed in the writing don't permit a nondestructive investigation of cursive written work writings, which speak to a genuine impediment in archive examination.