He was portrayed by Patrick Fabian.
During his time at the Los Angeles Telegraph, he had won the Pulitzer Prize. His work interfered with his marriage to Linda Martin and they separated. However, Reese desperately wanted to work out their issues and get back together.
Some time during the events of Season 1, Reese found out that the Lux nightclub owner Lucifer Morningstar was sleeping with his wife. Even though he and Linda had been separated for two years, he wanted revenge on Lucifer. He accidentally sees Lucifer's devil face and tries to tell Linda that Lucifer really is the devil. She does not believe him and forces him to sign the divorce papers.
Reese spent the next year trying to find proof that Lucifer is the devil. After a run-in with Lucifer at his office, he decided to test Lucifer's invulnerability. Reese interrupted Linda's therapy session with Lucifer. He shot Lucifer, who remained unharmed. However, by this time, Linda already knew that Lucifer is the devil. Reese was upset by her actually being friends with him and decided to leave, even though Linda tried to make amends with him.
He tries to convince a serial killer to kill Lucifer but the killer decides to kill Reese instead. However, Reese gets the last laugh as he tells the killer he's caught him as police sirens are heard (Reese previously informed Linda to call Chloe to turn himself in after revealing his role in the killer's recent killing) outside the building. Reese tries to stop the killer who fled the office only for Chloe to stop him.
At the end of the episode, it is revealed that he was trapped inside a loop as a part of his own personal hell, driven by his own guilt, which is actually what sends souls to Hell, according to Lucifer.