Intentional homicide, a declining phenomenon in Italy, represents one of the most extreme forms of violence. A specific subgroup of homicidal assailants is represented by those affected by mental disorders, where the relationship between psychopathology and characteristics of the homicidal attack is not yet fully understood. We analyzed the case files of 187 homicides or attempted homicides, in which the defendant had undergone a forensic psychiatric evaluation within the previous 10 years from a single forensic psychiatric center. We described and analyzed the perpetrator, victim and criminological characteristics of the study cases. A diagnosis of a schizophrenia spectrum disorder, a victim who was the perpetrator's biological child and absence of a personality disorder diagnosis were associated with an increased probability of having been adjudicated as lacking or having substantially diminished criminal responsibility due to a mental disorder. Homicidal assailants with a schizophrenia spectrum disorder showed some differences in criminological characteristics compared with murderers without a schizophrenic spectrum disorder, including a higher incidence of parricide, interruption of pharmacotherapy before the crime and disorganized post‐crime behavior.