Complex sentence: He does however have good intentions and wants Billy to make something of himself, which he knows he can, and can also empathize with Tepper as Parker was himself a tearaway at Tepper's age.
Split into simpler sentences: He does however have good intentions and wants Billy to make something of himself, which he knows he can. Parker can also empathize with Tepper, as Parker was himself a tearaway at Tepper's age.