‘Beyond devastating’: Relatives, co-workers remember Antioch woman killed in Mundelein mass shooting
Nicole Heiser reportedly knew from a young age that she wanted to work with animals.
According to her online professional biography, Heiser made that dream come true, most recently at GreenTree Animal Hospital in Libertyville.
Heiser, 37, of Antioch, was among the four people fatally shot by her boyfriend, Bryan Schmidt, on Sunday at his parents’ home in Mundelein, authorities have said. Schmidt also killed his parents, 80-year-old James Schmidt and 77-year-old Rebecca Schmidt, and his 22-year-old son, Maclaine, before killing himself.
In a Facebook post Wednesday, GreenTree employee Diana Pop called Heiser “one of the most profoundly good human beings I’ve ever had the privilege of knowing and calling my friend.” Heiser’s death, she said, “is beyond devastating.”
“Some people come into our lives and leave a mark on our hearts that will never fade,” Pop wrote. “The world is a lot less beautiful without her in it.”
The GreenTree staff collectively addressed Heiser’s death in a different Facebook post without naming her.
“Our team is navigating a difficult time and appreciates your patience, kindness, and understanding as we support one another,” the post reads. “We are prioritizing our staff's well-being and ensuring dedicated counseling support is available to everyone on our team.”
The post asked for privacy and went on to thank people for their compassion and support.
Heiser’s body was among five discovered late Sunday night by Mundelein police after someone requested a well-being check at the house.
The slayings likely occurred between 11 a.m. and 2 p.m. Sunday, police have said. Suicide notes were found in the house and in Bryan Schmidt’s vehicle, police said.
Detectives also recovered two handguns they believe Schmidt used in the shootings.
Mundelein police had no history of emergency calls at the Schmidt home nor recorded encounters of any kind with Bryan Schmidt.
Heiser graduated from Carroll University in Waukesha, Wisconsin, with a biology degree and a minor in animal behavior, according to her LinkedIn page and her professional biography.
Before joining the staff at GreenTree in 2024, Heiser spent 13 years working at the Northern Illinois Cat Clinic in Libertyville — a facility owned and operated by the Schmidt family until it closed a year or two ago.
Although she worked with a variety of animals at GreenTree, cats held “a special place in her heart,” the GreenTree website says.
According to the site, Heiser and Bryan Schmidt, 51, lived together and had two dogs, Cody and Phoebe.
Heiser’s brother-in-law, Paul Delfeld, launched a GoFundMe online fundraiser to help pay for her funeral and burial. More than $10,000 had been donated as of Wednesday afternoon.
On the homepage for the fundraiser, Delfeld described Heiser as “a caring, beautiful soul who cared deeply for her family.”
“One would be hard-pressed to find another person more loyal than Nicole,” Delfeld wrote. “She had an unparalleled love for animals and dedicated her life to caring for them as a veterinary technician.”
Heiser and Bryan Schmidt had been in a relationship for 11 years, Delfeld wrote.
“My wife and mother-in-law are in pieces, trying to make sense of everything,” he wrote.
Mundelein police, the Lake County Major Crime Task Force and the Lake County coroner’s office are investigating the killings. Anyone with information can call police at (847) 968-4600.
rlissau@dailyherald.com