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Prior to the Fall of the Twelve Colonies, he worked in the public litigation office on Caprica, where he likely met and learned from Joseph Adama, a man whom he hated yet respected. His parents were kidnapped, robbed and murdered when he was nine. He was married for 10 years to Faye Lampkin, with whom he had two daughters, Jennifer and Kate, and lived on Gemenon. The only memento of his family is his wife's cat, Lance, that he was picking up from the vet during the Fall; he claims to dislike Lance, but appreciates that at least it does not "scratch or bite like she did" ("The Son Also Rises", "Sine Qua Non").
Lampkin is appointed Gaius Baltar's defense counsel after his previous lawyer, Alan Hughes, is killed by a bomb planted in Margaret Edmondson's Raptor. He claims to take the case for the fame and glory, and despite questions raised about his previous experience, appears insufferably self-confident and pompous (The Son Also Rises). Further, payment for his services is rendered in the form of a compartment on a ship with a view, which he receives (Sine Qua Non).
Lampkin becomes the next assassination target, but is only injured when the door to his room is rigged with an explosive device. Consequently, Lampkin walks with a cane after being saved by Marine Henry Cheadle. A part he pocketed from Captain Aaron Kelly, identical to one used in an earlier unexploded bomb, reveals Kelly is the assassin (The Son Also Rises).
When Didi Cassidy, the prosecuting attorney, presents a compelling opening statement highlighting mankind's dwindling numbers, Lampkin changes Baltar's plea to "guilty". In another controversial and unusual move, he calls on Lee Adama, who joined the defense after a falling out with his father, to take the stand and testify on Baltar's behalf, gambling that Adama's testimony would be the best chance to sway the admiral's foregone verdict of guilty. Adama delivers an impassioned speech about how the Colonial Fleet and government forgave so many crimes and gave so many second chances, but not for Baltar, who is being offered up as a scapegoat for their own guilt, shame and failures. His testimony tips the tribunal's balance in favor of acquittal.
Lampkin says his goodbye to Adama after the trial and departs without his cane, walking without a limp, hinting to what extent the perceptions of both Adama and the court might have been manipulated (Crossroads, Part I & Part II).
After his "big win", Lampkin suffers the loss of Lance over a month later by "those debased dregs of humanity" who apparently kill the cat (possibly due to the fact that he defended Baltar in court) and is withdrawn until Lee Adama requests Lampkin's help in a search for an interim president. After eliminating a list of 47 candidates, including Doyle Franks, Lampkin submits Lee Adama's name to the Quorum of Twelve who ratify Adama's appointment, but not before testing him at gunpoint. He is given Jake, the dog that helped the Resistance on New Caprica, as a reward and as a new pet for him to loath as Lee Adama puts it. Lampkin says dogs are the only thing he hates more than cats, but he seems to accept Jake (Sine Qua Non).
After Admiral Adama is taken prisoner during Felix Gaeta and Tom Zarek's coup d'etat, Lampkin is called aboard Galactica by Zarek to serve as his legal council for a drumhead court-martial. Lampkin tries to get Adama to submit a testimony and stall for time while the military loyalists work to retake the ship and rescue the mutineers' hostages, but Adama refues. He convinces Lampkin instead that Zarek only brought him in to lend legitimacy to the process and intends to execute them both once Gaeta has been placated. When Adama is found "guilty" of his crimes, Zarek has marine Parr escort Lampkin away, presumably to his death, but along the way they happen upon the aftermath of Lee Adama and Kara Thrace's rescue of the Cylon hostages. Using Thrace as a distraction, Lampkin kills Parr by repeatedly stabbing him with a fountain pen and breaks free of his bonds. He ponders fleeing for a moment, but instead helps Thrace then carry a critically wounded Samuel Anders to Doc Cottle for medical treatment (Blood on the Scales).
In what he calls "poetic justice", he is appointed President of the Colonies before Galactica embarks on its rescue of Hera. He departs on the last Raptor off the ship to the salutes of Adama and the crew.
He, along with the last remnants of Colonial civilization, rejoins Galactica over the second, new-found Earth to settle and begin a life. He appears to be surprised that people of the fleet agreed to destroy their advanced technology and become primitive (Daybreak, Part II). As the Colonial government is dissolved following the settlement of Earth, Lampkin served as the final President of the Twelve Colonies.
Legal Practices and Ego
One of the best (not to mention only) legal experts in the Fleet, Romo Lampkin is known for his various quirks. Among them, Lampkin claims that interrogation rooms give him "stage fright". He also channels his kleptomania to his advantage by stealing objects he believes might give him insight or handicap his opponents. For instance he steals Laura Roslin's glasses, figuring that without them the president would appear less serious during the trial; and steals Gaius Baltar's pen to raises suspicions that Baltar is being silenced, and to use in a ploy on Caprica-Six. Romo Lampkin typically wears a pair of sunglasses, letting him observe and read those around him without giving anything away himself (The Son Also Rises).
Further, Lampkin is not above court room theatrics, which includes faking a limp during Baltar's trial and putting Lee Adama on the stand to sway the vote of William Adama (Crossroads, Part I & Part II).
Lampkin also codifies a set of "Lampkin's Legal Dynamics", the first of which he reveals to Lee Adama:
Further, he is not above testing people, as he does to Lee Adama, whom he threatens at gunpoint in an attempt to determine Adama's readiness for his role as interim president (Sine Qua Non).