Patti,,,,,fingernail " jabs " such as the marks on Neville's arm would be more prominent given the age of him,as with those who are older,any,even slight injuries would bruise easier than that of a younger person.
Though his build along with his health would have prevented a worse attack by fingernails.
I would bet that the one wound on June was more prominent. Women with nails like that can,and have done a lot of damage in crime scenes.
Because Sheila's nails were looked after and well manicured,they would by their very nature have been strong and not prone to breaking upon impact/contact,as in a struggle. She was young as well,and what I'm saying is that had she been a lot older,then the nails wouldn't have had the same impact,but would still wound.
Professor Vanezis failed to make a report regarding the lacerations,simply because no examination took place beneath the fingernails.
It was stated that whoever made the lacerations,also carried out the murders.