Dave's a half-blood (his father was a muggle) who entered Hogwarts the same year as Charlie and Tonks. Honestly, he had a crush on her but never admitted it; his choice of career was influenced by her drive to being an Auror though.
He's a Ravenclaw, studious, methodical. He's very calm and hard to ruffle; but in an emergency he reacts quickly and precisely. He's not one who enjoys the adrenaline rush much though; in times when there is a choice, he'll settle for the office work.
He married shortly after starting full-time as an Auror, the sister of a Durmstrang student he met while trainees were put out to help during the TriWizard tournament.
His first son was a squib; he's currently working as an accountant in a muggle bank. His second son came many years later and has in fact not started Hogwarts yet (hpsixwords timeline), being of the ripe age of seven.