Richard Belzer's character John Munch helps a potential suicide recover and reveals to her that his father killed himself. In real life, Belzer's father killed himself when Belzer was 23 years old.
The title "Painless" is a homage to the title song of the movie M*A*S*H (1970) "Suicide is Painless".
At the beginning, the doctor says "We're doing an EEG to assess brain activity". The electroencephalogram (EEG), is a medical test used to measure the electrical activity of the brain.
Robert LuPone (Brooks Harmon) has appeared in three episodes of SVU (S5.E22, S14.E11, S20.E15), playing a different character each time. Sadly, the actor died age 76 on August 27, 2022, from pancreatic cancer. His appearance in S20.E15 "Brothel" in 2019 was his final acting credit prior to his death.
Det. Tutuola (Ice-T) says "Or a Psycho doctor, killer nurse, like they got in Jersey. Gets off watching people die". This is a reference to Charles Edmund Cullen (b.1960), an American serial killer and former nurse. He murdered dozens (possibly hundreds) of patients during a 16-year career, in several New Jersey and Pennsylvania medical centers, by administering lethal doses of medication to patients, until being arrested in 2003. He confessed to committing as many as 40 murders, at least 29 of which have been confirmed. Cullen was sentenced to 18 consecutive life sentences. As of 2024, he is still incarcerated at New Jersey State Prison in Trenton.