Presumably, Kevin grew up in Riverdale alongside Betty Cooper, his closest friend. Nothing is known about his home life beyond the fact that his father is the sheriff of Riverdale. There has been no reference about his mother.
Kevin assisted Betty, while she prepared for her outing with Archie, in which she would finally reveal her true feelings towards him. He reminded Betty that whiles nerves are acceptable, she must follow through. Just as Kevin looked out Betty's window, he made a shocking discovery, "Archie got hot", he proclaimed.
The next day, at school, he was introduced to Veronica Lodge. It was then that he informed her on the social scene of Riverdale. After being propositioned in the bathroom by Moose Mason at the Semi-formal, Kevin immediately alerted Betty. As the two of them arrived on scene of Sweetwater River, Moose made it known that he was not gay. They decided on skinny-dipping first and moving on from there, however, they never even made it to the water as Kevin stumbled upon the body of Jason Blossom, who had a bullet hole in his head.
Now that Archie had turned down Betty, and the possibility of them being a power couple is no longer an option, Kevin wanted to revisit his theory of Archie being gay, since no straight man had that a body like Archie's. The conversation shifted to the topic of another body, Jason's. Kevin was fine, if anything, he was more traumatized from having to explain to his father why he and Moose were out at the river. Kevin joined Betty in the front office, where a beautiful bouquet of flowers awaited her. An apology was written on the card by "V". He wondered who this was, soon realizing that it was short for Veronica, who sought Betty's forgiveness and friendship. And while Betty was quick to forgive and forget, Kevin wasn't.
Kevin and Betty entered the classroom, where their teacher was assigning partners for a project. Moose volunteered to pair up with Kevin, as they needed to talk, though Kevin didn't seem too pleased. Moose was hoping that the two of them could arrange another get-together. Kevin declined his offer, but not before acknowledging how attractive Moose was, yet they cannot be together, as Moose had too many demons. Kevin told him it's better if Moose stick with what he knows best, which is girls.
During lunch, Veronica wonders what it was that Moose wanted during class when he volunteered to partner with Kevin, though she already knew the answer. Kevin states that he doesn't even think Moose knows what's going on with himself. Although sexuality is fluid, and he was admittedly handsome in a classic, pre-accident Montgomery Clift kind of way, Kevin questioned if someone named Moose could actually be that fluid. Regardless, Veronica "shipped it". Of course, she did, she was a big city girl with loose morals, Kevin said, though he instantly regretted saying it afterward. What Kevin really meant is that Moose had a girlfriend named Midge. Despite how awful it may sound. Part of him wished that Moose would just stay in the closet. The three of them then joined Archie at the lunch table, where they urged him to play a song for him. However, Betty stormed off in tears soon thereafter, with Archie chasing after her.
The next day in the student lounge, he and Moose were confronted by Reggie, who was outraged that he was being considered a suspect in Jason's death despite Kevin and Moose finding the body. Reggie wondered what they were doing down by the river, and if being the Sheriff's son gave him a free pass. However, Betty advised Kevin to ignore Reggie.
After attending the Pep Rally the prior night, Kevin watched as his father and Mr. Weatherbee entered the classroom for Cheryl, who claimed that she was guilty, though they had no idea of what she was guilty of.
After discovering that Archie was at Sweetwater River on July 4th, Veronica wondered if he was being considered a suspect. According to Kevin, all of them are suspects in the murder of Jason Blossom, even him, at least that's what he was told by his father. All the talk about death led to his next suggestion, of binge-watching "Making a Murderer" on "Netflix". Unfortunately, Betty has to work on the paper, and Veronica has a date. He was shocked to discover that she was going out with Chuck Clayton. He's one of the hottest students in school, and the varsity football coach's son. In Riverdale, that's the equivalent of dating a Kennedy.
Following Veronica's date, Kevin could hardly withstand asking her how it went. In passing, Tina Patel and Ginger Lopez asked Veronica about the "Sticky Maple" Chuck gave her during their date. While she was clueless as to what this meant, Kevin and Betty were very much aware of the meaning. A notification then hit his phone. It was a post of Veronica and Chuck, with maple syrup edited onto the photo. Chuck claimed to have given her a Sticky Maple, which is a slut-shaming thing in Riverdale, Kevin explained.
Late in the night, with the help of Trev Brown, who pointed them in the right direction, Kevin, Veronica, Betty, and Ethel managed to sneak into the school after hours in order to find the team's "Playbook". They were surprisingly joined by Cheryl, who was wearing amazing thigh high boots, Kevin remarked. Just as Trev said, the found the Playbook in one of the lockers, which included Veronica, Ethel, and Betty's sister, Polly
The following day, in the student lounge, Kevin was notably depressed as he didn't have a date for the drive-in, making out with your boy or girlfriend at the movies is in some way, a right of passage. He accepted Veronica's offer for to two of them to go together, but he wasn't too thrilled.
Back at his house, Kevin asked his father if he could use the truck for the night. Before handing him the keys, Kevin's father instructed him to stay in the truck due to all the dangers associated with that side of town.
At the drive-in, Kevin and Veronica sat in the back of the pick-up, cuddled up together as the movie played. To their surprise Cheryl arrived shortly after and she joined them in the truck. Kevin then ran into a Southside Serpents as he left the snack stand; the same serpent that he had previously made eye contact with. It wasn't long before he and Joaquin were making out in the back alley. Kevin gave him his number, however, Joaquin was startled to learn that he was the Sheriff's son. But the two of them agreed to keep it a secret.
Kevin returned home, with his father, to discover that the house had been broken into and all the details of Jason Blossom's murder had been destroyed.
Kevin, Betty, and Jughead reconstructed Sheriff Keller's murder board, returning it to the state it was in prior to the stealing of the files, background checks, and all the video and audio tapes of police interviews. Unfortunately, there weren't any fingerprints left behind, so the police have no idea who the culprit is. Kevin then questioned and mocked Betty over her date with Trev Brown, wondering if mama Cooper was aware, and what it was that she was really hoping to accomplish. Betty states that her mother was out of town. She then admitted that it wasn't actually a date, rather an intelligence gathering mission. They needed to focus on the one thing they had access to that Kevin's father didn't, that being the students at Riverdale high.
Every fall, Riverdale High School puts on a Variety Show to show case the talent of its students, this year, Kevin was selected as the host. Each student had to audition for a spot in the show, he started with Archie, who failed miserably, the stage fright got the better of him, as Archie rushed off stage. Even though it compromised Kevin's artistic integrity, after a few choice words with Veronica, who reminded him that he had heard Archie sing on numerous occasions, Kevin left a slot open for Archie if he still wanted it. The night of the 75th annual Variety Show had finally arrived, as host, Kevin welcomed everyone in attendance.
Kevin learned from Betty that her sister, Polly had escaped from the Sisters of Quiet Mercy group home. The Coopers had yet to report the incident as they didn't want anyone to know about her pregnancy or that she ran away. Kevin agreed with Archie on getting the police involved despite her parents' hesitance, he suggested that they go to his dad, who would be discreet, but Jughead disagreed as his father would have to answer to the Blossoms. It wasn't long before the news of Polly's escaped spread, thanks to Cheryl, which Kevin alerted Betty and Veronica of.
In an effort to find Polly before the Blossoms did, Kevin joined in on the search party throughout Eversgreen Forest, where he split off with Veronica. The two talked about her on-going feud with her mother. Veronica hated fighting with her mom, but she crossed the line with forging Veronica's signature in order to further her affair with Fred Andrews. He wonders what follows if Hermione doesn't break. Veronica explained that during similar situations in New York, she'd go on a partying bender with her favorite celebrity gal-pal, her best gay friend, and dimwitted arm candy, which would come to include Josie, Kevin, Reggie. He wonders if they should invite Betty as well, as she could probably use a distraction, though with the Blossoms joining the search, Veronica remarked that Betty would likely have her hands full.
The four of them spent the night out at a club called the Roving Eye, in which they danced the night away. After finding a booth to cool down in, Kevin asked if the partying was helping with her current dilemma. Veronica explained that everything was taken from them when her father was arrested, but her mother sat her down, and told her there was one thing that no one could ever take from her, which was her name, yet that's exactly what her mother did, as if it meant nothing.
During a conversation being had by Kevin, Betty, Jughead, Veronica, Cheryl, Valerie, and Archie, in which they discussed Polly's current dilemma, Kevin referred to Cheryl's family as the "child snatching Blossom monsters".
Serpents Attack SoDale
The next day, after learning that Fred Andrews' crew quit on him the day of the SoDale project, Kevin, Archie, Jughead and Moose volunteered to help with construction and keep things on schedule until Fred could find a new crew. As they were about to start construction, Kevin pointed out to Hermione how much he loved her shoes. Unexpectedly, Kevin proved to be quite useful on the construction site, so much so that they suggested that he join the Riverdale Bulldogs, but Kevin preferred his contacts sports to be one-on-one. As the day came to an end, so did the construction, the boys returned to the trailer, but Moose forgot his phone on the project site, where he was attacked by two thugs, who warned him to stop construction.
Kevin, Archie, and Moose suspected that the attack could've been the work of the Southside Serpents, as they had lost their territory due to the construction. With the help of Joaquin, they infiltrated a Serpent hang out known as the Whyte Wyrm, where their plan consisted of them calling Kevin's father if they saw Moose's attackers. Once inside, Kevin was visibly terrified, though he managed to keep his composure, even as he lost a game of pool to Joaquin. Although the original plan was to call Kevin's dad, Archie decided to confront the Serpent that Moose pointed out as being his potential attacker, which didn't end well as they were vastly outnumbered. However, they were released by FP Jones, Jughead's father, and the leader of the Serpents.
Kevin became increasingly disturbed as Ethel Muggs read an extremely dark poem in front of the class. This led Veronica to wonder if she was okay, to which Ethel explained that her household was under distress due to her mother and father's constant fighting. Hoping to cheer Ethel up, Veronica invited her to have lunch with her at The Pembrooke, Kevin would be there she said, much to Kevin's surprise as this was the first he had heard of it. After their chat with Ethel in the lounge, Kevin approached Veronica, wondering what was driving her sudden urge to help. Veronica realized that Ethel's poem was a cry for help, the likes of which she vowed she'd never ignore, especially not after an incident that happened at her old school in New York, last year, where a girl named Paige transferred schools after Veronica and her best friend tormented her.
As planned, the next day, Kevin, Veronica, Ethel, Betty, and Hermione ate lunch together, however, Ethel wasn't hungry as her home life hadn't gotten any better. A couple days later, Kevin informed Betty and Veronica that Ethel's father nearly committed suicide after swallowing an entire bottle of pills.
Having learned that Jughead never had a birthday party, Betty suggested that they throw him one, which Archie insisted was a bad idea because Jughead hates his birthday. Kevin remarked that everyone says that but no one means it. However, according to Archie, Jughead did mean it, he was a lone wolf. Just after Veronica announced that Jughead's 16th Birthday Party would be inner-circle only, Kevin spotted Chuck Clayton enter the cafeteria, fresh off his suspension, headed towards Ethel. Kevin commented that Chuck's lats may have gotten bigger, but not that he would really care considering that Chuck is evil incarnate.
The following night, as everyone awaited Jughead and Betty's return from the double-feature at the Bijou, Kevin briefly chatted with Veronica, who questioned why Joaquin was invited despite their previous agreement of inner-circle only. Kevin explained that since Joaquin was his boyfriend, that made him inner-circle. Veronica then mentioned that she had just returned from a meeting with her father's lawyer, between his upcoming hearing and his possible involvement in Jason Blossom's Death, she was in a foul mood.
As Jughead returned to Archie's house, Kevin greeted him with a hug and then introduced him to Joaquin, quickly followed by Betty bringing out a cake, and everyone celebrating as Jughead blew out the candles. Their quiet little gathering swiftly turned into a full blow house party as Cheryl and Chuck crashed the event, accompanied by a few dozen classmates, which led Kevin to wonder why they were doing it, Veronica surmised it was payback.
Jughead reveals to Betty that he does not consider Kevin a friend, and is thus as indifferent towards celebrating with him (and Joaquin) as he is with the party-crashers. Meanwhile, as Kevin and Joaquin made out in the kitchen, they were interrupted by FP, Jughead's dad, who Kevin was quite familiar with, having been kicked out of the Whyte Wyrm by him. FP then asked Joaquin to show him to the bathroom, leaving Kevin alone in the kitchen, until he ran into Veronica, who was unaware that FP was Jughead's father.
The high point of the night started when Cheryl and Chuck introduced a game they called "Secrets & Sins", a game in which they would reveal all their secrets, which Kevin watched suspenseful from the sidelines, that is until the situation turned violent between Jughead and Chuck, resulting in FP ending the party.
Kevin attended the annual Homecoming dance with Joaquin as his date. The two of them watched as Archie and Veronica performed "Kids in America" on stage. Afterward, He and Joaquin slow danced, leading Kevin to reveal that he had never brought a boyfriend to such an event, in fact, it was the first time he actually had a boyfriend. His past relationships consisted of brief hook ups with closeted guys. Just then, their dance was interrupted. After previously being asked by Betty were Archie and Veronica were, Kevin was asked by Jughead where Betty was. Before telling him that she headed out to the hallway with Archie and Veronica, Kevin joked about them needed tracking devices. He then spotted his father from across the room, talking to Mayor McCoy, to whom he revealed that Jughead's father had just been arrested for the murder of Jason Blossom.
Breaking Up with Joaquin
At school the subsequent day, after the shocking revelation that FP Jones killed Jason Blossom, Kevin asked Archie, Betty, and Veronica how Jughead was holding up because to him, the entire situation felt surreal. Jughead wasn't doing well, he was at the Sheriff Station being grilled by Kevin's dad, Veronica said. Kevin stated that his father was simply doing his job, of course, he would ask Jughead questions, but Betty was furious that he was even being interrogated because FP was clearly innocent. Kevin reminded Betty that he had confessed, but she believed he could've been coerced, or he was possibly protecting someone, like Joaquin, who Alice saw talking to FP during Jughead's party. Kevin stopped her right there, refusing to allow them to drag his boyfriend into the mess.
After learning from Archie's mother that FP used his one phone call from jail to contact Joaquin, Kevin called him over to Archie's house, where they asked him about his call from FP. Joaquin claimed he was simply given a warning to lay low, but they weren't buying it, so Kevin asked him again if he knew anything, but this time as the sheriff's son, instead of his boyfriend. Joaquin admitted that he had always assumed that FP killed Jason. Joaquin didn't see FP pull the trigger, but on July 11th, FP called him in the middle of the night for a cleanup job at the Whyte Wyrm. He met with FP in the basement, and that's when he saw Jason Blossom's body laying on the floor, they stashed the body in the freezer and cleaned up the mess. Veronica then asked Joaquin if her father had anything to do with the murder, but he wasn't sure, all he knew for sure is that he overheard a conversation pertaining to a rich guy between FP and Mustang, the same Serpent that Archie got into a fight with at the bar. They demanded that Joaquin take them to Mustang's place, and if he didn't, Kevin would tell his father about the cleanup job.
At the City Centre Motor Hotel, Kevin, Joaquin, Archie and Veronica discovered Mustang's dead body inside the bathtub. However, Joaquin couldn't stick around for when the police came, so he and Kevin quickly left the scene of the crime.
With the heat coming down, Joaquin thought it best if he left town, so Kevin accompanied him to the bus station. Before boarding a bus headed for San Junipero, he and Joaquin shared one last kiss. Joaquin then told him about a contingency plan he and FP thought up.
That night, Kevin, Betty, and Jughead headed out to the highway off route 40, where Jason's car was torched, and under the old beat down Blossom Maple Farms sign was a duffel bag containing Jason's Varsity Jacket. Joaquin didn't know if it would help FP or hurt him, but whatever the case, when FP called him from jail, it was to tell him to forget about the plan as it was too dangerous. Back at Archie's house, they debated over the importance of the jacket, and why FP chose to keep it. If anything, it seemed like more incriminating evidence. Betty refused to accept defeat, so she began checking the pockets, and inside the lining of the jacket, she found a USB flashdrive, and so Kevin named her as Nancy Drew. On the flashdrive was surveillance video from the night Jason was murdered. Despite FP confessing to the murder, the video revealed that Jason's killer was his very own father, Cliff Blossom.
Following the suicide of Clifford Blossom, and the revelations that he was not only responsible for the death of his own son, Jason Blossom, but that he was also involved in heavy drug trafficking, Kevin informed his friends that his father told him that more and more drugs were hitting the streets of Riverdale. Kevin's father and Mayor McCoy believed this to be the workings of the Southside Serpents. In exchange for FP Jones' cooperation, they'd show him some leniency. However, Jughead insisted that the Serpents weren't responsible as his father was sure of it.
The next day at school, Kevin approached Jughead, and Veronica at the lunch table as they chatted with Cheryl, telling them that they needed to see something bad. Kevin directed them to Betty's locker, which had been written on in pig's blood, which read "Go To Hell Serpent Slut!".
The following night, Kevin attended the 75th Anniversary Jubilee, where he sat in the crowd as Betty gave a speech about the impending turmoil that the town was facing, and how that if they didn't fix it, Jason's death certainly wouldn't be the last. Afterward, he gave her a standing ovation, along with the rest of the crowd.
Kevin briefly appeared alongside his father in his graduation cap and gown, during Fred Andrews' hallucinatory vision, brought on by the gun shot he earlier sustained.
Meanwhile, in reality, Kevin arrived at Riverdale General Hospital after learning that Archie's father was shot at the diner by an unknown assailant wearing a black hood. He joined Betty in the lobby, where he asked about her relationship with Jughead, and if they had sex after the Jubilee. Betty informed Kevin that while she and Jughead didn't have sex, he did say that he loved her, and Betty reciprocated these feelings. Unfortunately, the night when downhill from there as Betty was concerned with Jughead possibly joining the Southside Serpents, which Kevin immediately warned her against. He advised her to review his past relationship with Joaquin, who was also a Serpent. Betty stated that Joaquin was nice, but only when he wasn't dumping bodies in Sweetwater River or mopping up buckets of blood, Kevin retorted.
After an awkward exchange of looks between the two, Kevin and Betty noticed Cheryl heading down the hall. From Cheryl, they learned that there was a terrible fire at Thornhill the prior night. She might have perished within the flames had her mother not saved her. After her ordeal at Sweetwater, where she attempted to kill herself, Cheryl was at home, asleep when the fire started. They believe the start of the fire was from a breeze knocking over a lit candle, which caught the curtains. Mrs. Blossom returned to Thornhill and rushed headlong into the blaze, risking her life to save Cheryl's, which unfortunately resulted in her suffering third-degree burns as well as acute smoke inhalation.
Kevin appeared in yet another one of Fred's dreams, this time at Archie and Veronica's Scottish themed wedding. He sat next to his father in the crowd as Veronica came down the aisle.
Kevin is a very outgoing, charismatic student who knows the social scene of Riverdale very well. Being an openly gay teenager, Kevin freely talks about other guys in public and has shown to have an interest in fashion as well. He has a tendency to make very blunt and honest statements about the people and events in the series.