|“||Everyone I killed, they were better of dead.||„|
|~ Lindsey before her death.|
|“||Please don't hurt me. I'm a mother.||„|
|~ Lindsey's last words.|
Although Lindsey was portrayed as a normal nurse, she soon turns out to be a serial killer as of 2015. On New Year's Day 2014, Rick Spencer is killed by an anonymous person; he is injected with potassium chloride, forcing him into cardiac arrest. Later, several other murders occur: Mariam Andrews, Charles S'Avage, Ashley Davidson, Dylan Jenkins, Will Savage and Phoebe McQueen. In October 2015, when Freddie Roscoe (her husband) is almost murdered, we see Lindsey for the first time. She explains it to her sister Kim Butterfield, saying that the main reason why she killed all of those people was to try to fill in the void she caused when she attempted to murder their other sister, Kath Butterfield, when they were children. It is revealed that Lindsey deliberately pushed Kath into a lake in the hopes of drowning her because she hated Kath; she believed Kath to be responsible for all of the fights that had happened within the family and Lindsey just wanted Kim as her only sister. However, another reason for Lindsey killing all of those people was so she could feel in control of her life again after losing the love of her life, Joe, when she had an affair with his brother Freddie, as well as the fact that she wanted to feel superior to her victims and feel like "The Angel of Mercy/Death". Lindsey also admits that she tried to kill Dianne O'Conner, but not Kim's ex-girlfriend, Esther Bloom.
Kim was initially shocked and disgusted by her sister's actions, but eventually decides to vouch for her whenever she gets into trouble because Lindsey is the only family Kim has left and doesn't want to lose her. Lindsey and Kim pin all of Lindsey's serial killings on Trevor Royle, until in February 2016 when Trevor's lawyer, Simone Loveday, finds hard evidence from Trevor's girlfriend, Grace Black, that Trevor didn't commit any of the murders and is immediately freed, much to Lindsey's anger. In the same month, Freddie returns to the village, unknown that Lindsey tried to kill him, and on the same day, Lindsey goes to get a retinal scan and she and Kim both discover that Lindsey is 4 months pregnant and not 2 months pregnant like she thought when she slept with Joe on New Years Eve 2015, which means that the baby is Freddie's. Later, Lindsey was thought to have attacked paedophile Pete Buchanan, but it is eventually revealed to have been his stepdaughter, Celine McQueen. Previously, Lindsey, Mercedes McQueen and Cindy Savage all killed Paul Browning together. Also, in February 2016, Lindsey decides to frame her own sister Kim for her heinous crimes, and Kim is charged with her evil sister's crimes. Kim was unaware until April 2016 that Lindsey deliberately framed her. Lindsey shows that she is completely remorseless for betraying her sister.
In April 2016, Lindsey is finally exposed by her former best friends, Mercedes and Cindy, and she knocks them out and tries to flee the village with Joe and JJ, but when Mercedes informs Joe that Lindsey is the killer, he starts to believe it and Lindsey notices that he is growing suspicious of her, so she knocks him out, too, and takes JJ. She arrives at the Roscoe garage, where Freddie is waiting and he confronts her about her unborn baby's true father. Wanting to escape before she is caught, Lindsey casually admits that the baby is indeed Freddie's. Soon after that, Freddie receives another flashback of the day he was almost murdered, and he finally remembers that it was in fact Lindsey who attacked him. Freddie is outraged and keeps Lindsey from taking JJ with her, causing her to flee the garage and hitch a ride with Frankie Osborne, who has returned from her long term holiday away. Lindsey kidnaps Frankie and calls her granddaughter, Esther, telling her to help her escape the country by getting Lindsey's passport, or else Lindsey will kill Frankie. After receiving her passport and leaving Frankie with Esther, Lindsey is about to get caught by the police, but she is helped by other infamous serial killer, Silas Blissett, who returned to the village in January 2016 (under the alias of Mr. Edward Mann) because he was fascinated with the Gloved Hand Killer case, and the two drive off together, foreshadowing that both serial killers will return to the village in the future to cause more trouble and to deal with old enemies (Silas will most likely come after Mercedes McQueen again).
Silas keeps Mercedes held hostage, and asks her to play some chess. The two have a conversation about Heidi and Riley. JJ starts crying, Mercedes sees to him, she picks up a nail file and attempts to kill Silas, but he sees it coming and stops her. The two sit down again, and Silas sees Mercedes' "Gabriel" necklace and asks her who Gabriel is. An emotional Mercedes bursts out at Silas and reveals that Gabriel is her dead baby son and tells him to kill her so that she can be with her baby again. Silas shows some surprising amount of remorse and sympathy towards Mercedes, saying that he understands what it's like to lose a child. He is also impressed by Mercedes' big change in character, becoming more maternal, thoughtful, and dressing almost respectably, but he states that none of that can erase her slutty past. Next, Mercedes reveals to Silas how Lindsey has been seeing Joe and Freddie at the same time, making her as much of a slut as, if not more of a slut than, Mercedes and any other woman Silas had gone after. Silas becomes enraged by this revelation. Lindsey locks Celine, Tegan, Freddie, Kim and Joe in the hospital and escapes with her baby. She arrives at the house where Mercedes and Silas are, Silas demands Mercedes to take the child upstairs. Silas corners Lindsey, telling her that he has a purpose for what he does and he is making the world a better place by cleansing it of its women who demean themselves, whereas Lindsey only kills people so that she can feel superior to her victims. Lindsey insists that he's got her all wrong, and Silas agrees, saying that he thought Lindsey was special, like someone he used to know (Lynsey Nolan), but he states that Lindsey is not even worthy of her name. Lindsey begs him not to hurt her because she's a mother, but Silas says that she's a slut and that her children and the rest of the world will be better without her, and he strangles her, thus ending the year long reign of the Gloved Hand Killer.