Dave Palmer is known as Diana's uncle and Lily Palmers brother. The problem is that we know Diana's dad is also named Palmer as the hospital in New York is named after him. The only logical option for all three having the same surname is that Dave Palmer is Diana's fathers blood brother.
After the death of Diana's father and Lily's husband. Dave has stepped up to look after them. Dave has never married. He brings a great balance to Lily and her disdain to the Phantom. He respects and occasionally asks for help. The Phantom respects him back.
In the war he was a major for Army Intelligence and became a war hero and reached the rank of colonel. Dave has a long experience within law enforcement after his career in the army. He became the Police Commissioner of New York, before moving on to politics and becoming Mayor for a short period of time. After that, he worked for the US government's anti-terrorism department. He is currently retired.
Dave smokes a pipe, has white hair including a mop near the fringe.
In Ray Moore created stories he looks different but you must draw him in the style that Sy Barry drew him.