Premiering April 27, 2025, on Lifetime, Murder at the Derby gallops into high-stakes suspense with a tale of ambition, jealousy, and peril at a prestigious horse stable. At the heart of the chaos is Kara Miller (Ronni Hawk), a determined newcomer caught in a web of family rivalry orchestrated by Jennifer Rosemont’s volatile brother, Stephen (Daniel O’Reilly). Rounding out the cast are Kate Watson as the enigmatic mentor Jennifer, Brittany Underwood as a sharp-witted director, and John F. Hayes as a cunning writer. Dive into the careers of this dynamic ensemble bringing the thriller to life.
The Cast of Murder at the Derby
1. Ronni Hawk as Kara Miller
Born on December 9, 1999, in Lake Worth, Florida, Ronni Hawk skyrocketed to fame as a Disney Channel star in Stuck in the Middle (2016–2018), showcasing her comedic flair and relatability. She later transitioned to edgier roles, like Hailey in Netflix’s On My Block (2018), proving her range in dramas tackling teen struggles. After a brief hiatus to focus on mental health advocacy, Hawk returned with Lifetime’s Girl in the Shed (2023), a role that honed her ability to portray resilience under pressure—a skill crucial to her portrayal of Kara.
Hawk’s career mirrors Kara’s journey: both navigate high-stakes worlds with grit. Off-screen, she’s an outspoken advocate for mental health, using her platform to destigmatize therapy. In Murder at the Derby, her wide-eyed ambition clashes with Stephen’s menace, echoing her real-life evolution from Disney darling to mature storyteller. Up next, she’ll produce and star in an indie project about youth activism, cementing her commitment to meaningful roles.
2. Daniel O’Reilly as Stephen Rosemont
London-born Daniel O’Reilly (born May 29, 1988) first gained notoriety as “Dapper Laughs,” a controversial comedy persona that sparked debates about misogyny in media. After stepping back from the character, he rebranded with gritty acting roles, including the crime drama Vigilante (2022) and the dark comedy Bloods (2021–2023). As Stephen, Jennifer’s jealous brother, O’Reilly channels his knack for intensity, balancing menace with a twisted vulnerability that makes the character unnervingly relatable.
O’Reilly’s career reinvention parallels Stephen’s desperation to control his legacy. Off-screen, he’s become an advocate for mental health and addiction recovery, openly discussing his past struggles. His role in Murder at the Derby marks his U.S. television debut, a calculated leap into darker, character-driven narratives. Later this year, he’ll star in the British thriller Redemption Road, but first, Stephen Rosemont proves O’Reilly’s mastery of morally complex roles.
3. Kate Watson as Jennifer Rosemont
A rising star from Toronto, Kate Watson (born August 12, 1995) cut her teeth in indie films and stage productions, earning praise for her nuanced performances in dramas like The Quiet Storm (2021) and Beneath the Surface (2023). As Jennifer Rosemont, the seasoned horse trainer mentoring Kara, Watson draws from her own journey navigating competitive industries—a theme that resonates with her advocacy for gender equity in film and equestrian sports.
Watson’s grounded presence adds gravitas to Jennifer, a role that required months of horseback training. Off-screen, she’s a vocal supporter of animal welfare, partnering with equine rescue organizations. Though Murder at the Derby is her biggest TV role to date, Watson’s theater roots shine in her layered portrayal of a woman balancing mentorship with survival. Fans can next catch her in the period drama Gilded Hearts, premiering late 2025.
4. Brittany Underwood as Director
Brittany Underwood (born July 6, 1988) first captivated audiences as Dr. Emily Peterson on The Young and the Restless (2009–2011), followed by a starring role in the Lifetime thriller A Mother’s Suspicion (2019). A multihyphenate talent, she’s also a singer-songwriter with two albums blending pop and soul. In Murder at the Derby, Underwood plays a shrewd director entangled in the stable’s secrets, a role that mirrors her real-life hustle as both artist and entrepreneur.
Underwood’s career defies boxes: she’s hosted reality competitions (Queen Boss), produced short films about female empowerment, and launched a lifestyle brand for creatives. Her character’s no-nonsense demeanor in Murder reflects Underwood’s own journey navigating Hollywood’s challenges. Later this year, she’ll drop a new single and star in the rom-com Love, Unscripted, but first, her turn as the director adds a meta-layer to Lifetime’s signature suspense.
5. John F. Hayes as Writer
John F. Hayes, a seasoned writer-director known for Lifetime hits like The Wrong Real Estate Agent (2022), steps in front of the camera as a cunning writer embroiled in the Derby’s intrigue. Born in Vancouver, Hayes (born 1980) began his career scripting thrillers for Canadian TV before crossing into acting with cameos in his own projects. His dual role here—both as actor and behind-the-scenes storyteller—adds a playful twist to the film’s themes of manipulation and control.
Hayes’ meta-casting blurs lines between creator and character, a nod to Lifetime’s savvy audience. When not penning scripts, he mentors emerging filmmakers through workshops focused on suspense storytelling. His upcoming directorial effort, Shadow of the Ridge, promises more edge-of-your-seat drama, but in Murder at the Derby, Hayes relishes playing a wordsmith whose secrets could unravel the stable’s legacy.
