Damon is a gay lawyer that worked with Katie Spencer when she was D.A of Gotham. Katie stole his card to get into the evidence locker and became the superherione known as Manhunter after stealing lots of equipment. Damon did not know this but kept living his life including dating Todd Rice, the superhero known as Obsidian. Damon was brought to the boss and when they talked about his I.D opening the evidence locker he had no clue and was evidently fired. Katie then quit as well before coming clean to Damon that it had been her and she was Manhunter. Katie seemed to have made a deal with Mr. Bones for both of their jobs.
For more information see: Street Justice
Damon helps his boss Kate Spencer, in Los Angeles, during the trail of Copperhead. He is believes she did a great job and shocked just like her when verdict comes back Not Guilty by reason of Genetic Anomaly. Later Kate steals Damon's restricted access Id card, an act that would later come back to haunt Damon and Kate.
The next day it is Damon who calls Kate and tells her that the press wants to speak to her about the death of Copperhead, and act that Kate knows a lot about.
A few days later, when a group of JLAers show up at the Damon can't help but gush over all over them. He takes to them to see Kate, wondering why the JLA is looking for Kate.
DC's New 52
After the reboot of 2011, Damon was a lawyer again. He helped Maggie Sawyer to get custody for her daughter Jamie Sawyer.