>>1945878 (lb)
Acid, or by grafting other skin onto your fingertips…
>Dr. Howard L. Updegraff, a member of that committee, had extensive experience in the area of fingerprint alterations and he reported that the only way to permanently obliterate a fingerprint is to graft skin from another part of the body over them. And in 1941, that’s exactly what Robert Phillips did when he got a doctor to graft the skin from his chest on to the tips of his fingers. Phillips, however, was caught because the ridges surrounding the graft areas, as well as on the other joints of his fingers were used to identify him.
>Dillinger seemed to have taken the road less traveled when he chose acid to burn the tips of his fingers with in late May, 1934. The procedure appeared to be successful; however, faint ridge markings were still visible on his fingertips after the full healing process, as were seen after Dillinger’s death.
https://www.crimemuseum.org/2009/05/18/john-dillinger-fingerprint-obliteration/