They were first introduced by Vincent Griffith in For the Next Millennium, so they can work together to solve a series of murders happening in New Orleans. After Lucien compels him however, Will is unfit to work in a police environment. The two shared a distant relationship throughout the first half of the third season.
Their strained friendship came to an end after Camille died in No More Heartbreaks. Will became aware of her death and his compulsion was starting to wear off a little which left him with questions that were answered by Vincent.
Throughout The Originals Series
In For the Next Millennium, Vincent introduces Cami to Detective Will Kinney as a shrink, to help them solve a murder case. After examining the body Cami informs Will that the murder looks methodical and precise. She also warns him that the killer did it intentionally and he might do this again. Later Will calls Cami and tells her that she was right and they found another dead body killed in the same manner as before.
In You Hung the Moon, Will goes to Rousseau's and asks Cami for a drink. While pouring him a drink Cami advices Will to consult someone with a little more experience as she is not a forensic psychologist. He agrees and then asks her about Klaus Mikaelson the mysterious philanthropist-slash-artist. To avoid the topic Cami tells him that she is not allowed to discuss her clients. At which Will says he knows about her past, implying how her brother and uncle died. Cami gets nervous and asks him if he is accusing her of something. To which he has no prove but he promises that he will find out. Came later realizes that detective Kinney stole her laptop while they were talking. But he couldn't find anything in her laptop as all the interesting stuff was password-protected. But he watches an video of Lucien Castle, he guesses Cami must have suspected him as the killer as he fits the profile of a narcissistic personality disorder.
In The Axeman's Letter, Will finds Cami at a crime scene and suspects her involvement in the murder. Later he barges in to Kieran's Secret Apartment, while Cami was showing all of the dark objects to Vincent, and arrests her while taking all the dark objects into custody as evidence.
In Beautiful Mistake, both Cami and Will are kidnapped by Lucien. As revenge for Cami constantly trying to spy on Lucien, Lucien compels Will to forever feel worthless because he cannot solve a case. Cami pleads with Lucien to take back the compulsion, but Lucien rejects her pleas.
In Savior, Cami goes to Will's house because she feels bad for him due to Lucien's compulsion. Klaus appears and they both abruptly stop Will's attempt to commit suicide. Cami asks Klaus to compel Will to feel better about himself, which Klaus gladly does for Cami and Will.
In Wild at Heart, Will is surprised at the fact that Cami compelled him to commit a felony for her. This may have strained their friendship.
In Give 'Em Hell Kid, Will pays his respect at Cami's wake and is quite suspicion about how she died having been compelled to forget about the supernatural world of New Orleans. He's eventually told the truth by Vincent and Will helps avenge Cami on his part.
- Will (to Vincent about Cami) : "Is this your friend the shrink?...Will Kinney. Detective-- homicide."
- Cami (to Will) : "Cami O'Connell-- bartender, part-time shrink..."
- Will (to Cami) : "So, cops want a psychological profile, and, given what we've found, I'd say this is your area of expertise."
- Will (to Cami) : "Hey. It's just me!"
- Cami (to Will) : "Maybe not the best time to be sneaking up on people?"
- Will (to Cami) : "Sorry. It's been a long night. I saw you walking in. Thought you might not mind pouring me a drink."
- Will (to Cami) : "You know, I've seen you in town before... with Klaus Mikaelson. Mysterious philanthropist-slash-artist with no past on record? Is he a friend or a patient?"
- Cami (to Will) : "You know, I think we should call it. I'm not allowed to discuss my clients."
- Will (to Cami) : "I know who you are."
- Cami (to Will) : "Right. My brother murdered a church full of seminary students, so my name must be familiar to the local PD."
- Will (to Cami) : "It is. But when Vincent brought you in, I did further research."
- Will (to Cami) : "For example, your uncle Kieran's death last year-- that autopsy report was just full of plot-holes."
- Cami (to Will) : "He had a heart attack."
- Will (to Cami) : "Perfectly rational explanation. There's always a perfectly rational explanation. Your family has a whole century full of strange deaths. Unexplainable behavior. Grave-robberies. Beheadings. Missing persons. Police reports with entire sections blacked out. Whenever there's a problem in the Quarter, there's an O'Connell... either causing it, or cleaning it up."
- Cami (to Will) : "Are you accusing me of something?"
- Will (to Cami) : "No. I just think your whole "good Catholic family" thing is a cover. I just haven't figured out what you're covering yet. But I will."
- In The Axeman's Letter, Cami was arrested by Will. Moreover all of the Dark Objects in her possession were also taken by him as evidence.
- Both of them were kidnapped by Lucien Castle in Beautiful Mistake.