The Cook County Medical Examiner's Office ruled 30-year-old Theodore Hilk's death an accident and said the cause of his death was lidocaine toxicity.
RELATED | 'Chemical compounds' removed from Streeterville high-rise where bomb-making materials, body found, CPD says
Lidocaine is used as a treatment for arrhythmia, and it's also been used as a cutting agent for some drugs.
Police were conducting a well-being check when they discovered Hilk's body. They also found and removed potentially explosive chemicals inside his apartment.