CHICAGO (CBS) — An Evergreen Park doctor who died of a self-inflicted gunshot wound last fall left behind a suicide note that suggests he didn’t provide vaccinations to some children whose parents had asked for them, authorities said.

Dr. Van Koinis was found dead in a Cook County Forest Preserve in Palos Township on Sept. 10, 2019.

The Cook County Sheriff’s office said its investigation of Koinis’ death by suicide revealed questions about his record-keeping practices.

“Investigators found that discerning who received vaccinations and who did not was unclear due to record keeping issues. Investigators also obtained information that suggests Dr. Koinis, a pediatrician, in some cases did not provide vaccinations to children at their parents’ request,” the sheriff’s office said in a statement.

Koinis ran a practice at 3838 W. 95th St. in Evergreen Park, and had been licensed to practice medicine in Illinois since 1991, the sheriff’s office said.

Investigators are encouraging his former patients to speak to their current doctors to decide if they need to be tested for prior vaccinations.

Anyone with information about Koinis should call the sheriff’s office at 708-397-633.

Former patients with questions about personal or family medical records can call a special hotline at 630-670-1673.