Jonathan Leroy

The following is a list of characters that first appeared in the BBC soap opera ''EastEnders'' in 2003, by order of first appearance.

Dominic Price

Detective Inspector Dominic Price, played by Paul Brennen, is first seen in March 2003, while his colleague, PC Kate Morton (Jill Halfpenny) is undercover as a honeytrap on Phil Mitchell (Steve McFadden), investigating the disappearance of Lisa Fowler (Lucy Benjamin), mother of Phil's daughter Louise Mitchell (Rachel Cox).

He mainly helps Kate with initial searches of the Mitchell house, constantly reminding her that "the boss" wants to nail Phil. He later starts to suspect that Kate is developing feelings for Phil, and reminds her that Phil could be a murderer. Kate gives Phil an ultimatum: to tell the truth about Lisa's whereabouts or she will finish with him. After Phil calls her bluff and finishes with her, Price takes Kate off the case, however, after Phil phones her and says he will tell her everything, she is congratulated by "the boss" – DCI Jill Marsden (Sophie Stanton) – who has wanted to convict Phil since 2001.

Kate goes to the Mitchell's house wearing a wire, and hears Phil's confession that he had mentally abused Lisa into handing over Louise, leaving her in Portugal. After this, Kate takes off her wire, telling Price and Marsden that she has fallen in love with Phil. They stick around outside, hoping that Kate has changed tactic and is still on their side, but they cannot hear what is happening as the wire has broken, so Marsden calls Kate's mobile phone, which leads to Phil discovering the wire. After a heated argument, Price and Marsden storm into the house to find Phil with his hand around Kate's throat. She refuses to press charges so they cannot arrest him, and they have to leave, deflated.

Price appears again in May 2003 when Kate returns to work and is asked to choose between her job and Phil. She chooses to resign, and asks Price for one last favour as a leaving present: to get George Peters (Andy Beckwith) arrested for dealing cocaine. George is a heavy employed by Jack Dalton (Hywel Bennett), who had been sent to rape Kate.

Price and Marsden later appear in November 2003, when Den Watts (Leslie Grantham) and his son Dennis Rickman (Nigel Harman) set Phil up for armed robbery; this time they are successful in convicting him, keeping him in custody until his case collapses in 2005. In late 2004, an off-duty Price visits Kate, now running a salon, and she tells him she is bored of her career. He finds her another job in the police, based in Brighton, which causes her to leave Walford the next day.

Dennis Rickman

Dennis Rickman, played by Nigel Harman, is introduced as the hardman successor to the character of Steve Owen (Martin Kemp), who was killed off in the series in 2002. Dennis makes his first appearance on 14 April 2003. His storylines involve his difficult past and childhood, relationship with his infamous father, Den Watts (Leslie Grantham), clashes with the rival Mitchell family, and a forbidden romance with his adopted sister, Sharon Watts (Letitia Dean). He is described as the show's "bad boy pin-up character." In 2005, Harman quit the show alongside co-star Dean, and makes his last appearance on 30 December 2005.

Mickey Miller

Mickey Miller, played by Joe Swash, makes his first appearance on 15 April 2003. Introduced as a guest character, Mickey proved popular and was turned into a regular by executive producer Louise Berridge. The character is portrayed as a wheeler-dealer