O'Laughlin began a relationship with Van Pelt after she and Wayne Rigsby broke up. He played high school football against her father's teams. He played in the NFL until he was injured. Their relationship progressed and the two of them got engaged and started planning their wedding. Over time, however, he was revealed to be a coward as he wasn't willing to risk himself to protect Van Pelt during a shootout with a suspect. Van Pelt didn't notice O'Laughlin's cowardice, but Rigsby did -- and made sure he had her back.
In the episode "Strawberries and Cream", O'Laughlin was revealed to be the CBI insider for Red John, and also Todd Johnson's killer. At the mountain cabin where Madeleine Hightower was hiding, he killed two police officers; got the drop on Teresa Lisbon, Hightower, and Van Pelt; and shot Lisbon, wounding her in the shoulder. He then held his gun on Hightower and Van Pelt, intending to kill them. However, Lisbon threw a pillow at O'Laughlin from the floor, distracting him and spoiling his aim, and he was shot by Van Pelt and Hightower.
At the beginning of the confrontation, as O'Laughlin held his gun on Van Pelt and Hightower, he stated he had grown fond of Van Pelt, suggesting that his love for her was all originally a farce just so he could be close to Lisbon's team to be a spy for Red John. After he was shot, with his last breath, he reached toward Van Pelt and tore off the heart necklace he had given to her.
In the 12th episode of Season 4, he reappeared as an hallucination after the evidence laboratory returned the heart necklace to Grace Van Pelt and she was involved in a car accident. He helped Grace Van Pelt as a figment of her imagination to find her way through the countryside when she was lost with a witness. In the end, it turned out that the witness was, in fact, the murderer. Van Pelt's hallucination of Craig shouted a warning when the murderer tried to kill Van Pelt. After commenting about how his debt was paid (he once tried to kill her, now he's saved her), he vanishes as Rigsby and a rescue crew emerge from the scenery. In Green Thumb, his name was seen on a fake list of Blake Association members.
In his murders he uses the same modus operandi of Todd Johnson himself, a friend of Red John's: fire, guns and cutting.
- Todd Johnson (set on fire)
- Manuel Montero (stabbed in the back)
- Officers Cole and Mayers (shot in the head)
- In the earlier episodes, the DVD subtitles spell his name "O'Loughlin", but correct this in later episodes.
- It is revealed by Kimball Cho in the episode Red Carpet Treatment that in Craig O'Laughlin's curriculum it appears that he has a degree in Criminology in the Ivy League, is a former member of the 101st Airborne Division and is a black belt in Wushu/Kung Fu, more precisely black belt in Shaolin Kung Fu.