Nicole Heiser dedicated her life to a passion she had nurtured since childhood: caring for animals. A 37-year-old female, she was remembered by loved ones as a bright, compassionate, and profoundly good human being who was loyal beyond measure. Her family described her as a caring, beautiful soul who cared deeply for them and had a great reverence for the natural world. This love for animals defined her career as a veterinary technician, where she was known as an esteemed animal empath.
Cats held a special place in her heart. After graduating from Carroll University in Waukesha, Wisconsin, with a degree in biology, she worked for 13 years at the Northern Illinois Cat Clinic in Libertyville. In 2024, she joined the staff at GreenTree Animal Hospital, also in Libertyville. She and her long-term boyfriend, Bryan Schmidt, lived in Antioch with their two dogs, Cody and Phoebe.
On the evening of Sunday, October 18, 2026, a concerned family member, unable to reach their relatives, requested a well-being check at a home in the 200 block of Wellington Avenue in Mundelein, Illinois. At about 11:45 p.m., Mundelein police officers entered the house and made a devastating discovery. Inside, they found five adults who had all been fatally shot. Investigators believe the shootings occurred hours earlier, sometime between 11 a.m. and 2 p.m. that day. A neighbor later recalled hearing what sounded like firecrackers just before noon but thought it was children playing.
The deceased were identified as Nicole Heiser; her 51-year-old boyfriend, Bryan Schmidt; his parents, James Schmidt, 80, and Rebecca Schmidt, 77, who owned the home; and Bryan's son, 22-year-old Maclaine Schmidt. The Lake County Coroner's Office determined that Nicole died from a single gunshot wound to the head. James and Rebecca Schmidt died from multiple gunshot wounds, while Maclaine Schmidt also died from a gunshot wound to the head. Bryan Schmidt’s death was caused by an intraoral gunshot wound and was ruled a suicide.
The investigation, conducted by Mundelein police detectives, the Lake County Major Crime Task Force, and the Lake County Coroner's Office, concluded that the incident was a quadruple murder-suicide. Authorities determined that Bryan Schmidt shot his parents, his son, and Nicole before taking his own life. Detectives recovered two handguns at the scene. They also found multiple suicide notes left by Bryan Schmidt inside the house and in his vehicle. Police reported having no prior contact with Bryan Schmidt or his family.
In the wake of the tragedy, Nicole's family released a statement, refusing to let her be defined by the horrific violence. "Nicole was loyal beyond measure, generous in her time, and an esteemed animal empath," they said. "We are so grateful for our beautiful time together and feel her presence strongly in our precious memories and calm winds." A colleague from GreenTree Animal Hospital, Diana Pop, remembered Nicole as "one of the most profoundly good human beings I’ve ever had the privilege of knowing and calling my friend," adding that "the world is a lot less beautiful without her in it."
The staff at GreenTree Animal Hospital posted on Facebook about navigating a difficult time and ensuring counseling support was available for the team. Nicole's brother-in-law, Paul Delfeld, created a GoFundMe page to help with funeral and burial expenses, describing the immense grief his wife and mother-in-law were experiencing. On the fundraising page, he wrote, "One would be hard-pressed to find another person more loyal than Nicole."
As of October 2026, the investigation was considered closed, with the perpetrator deceased. The Mundelein Police Department asked anyone with information about the incident to contact them at 847-968-4600.
