In People v. Brown, 225 Ill. 2d 188, 201, 866 N.E.2d 1163, 310 Ill. Dec. 561 (2007), the defendant's murder conviction was reversed where the medical evidence failed to establish the defendant's stabbing caused the victim's death. In that case, the victim was hospitalized shortly after the stabbing. She was released a week later. Three days after her release, she was readmitted to the hospital after a wound opened. That night, she died. At trial, her treating physician testified the cause of death was a pulmonary embolism--the lodging of a blood clot in the main artery of her lung. Because the victim did not suffer other risk factors associated with blood clots, the doctor concluded the clot originated from the victim's stab wound site and traveled to her lung, causing her death. The reviewing court held the State failed to prove the "essential causative relationship between" the defendant's act and the victim's death. Brown, 57 Ill. App. 3d at 532. The court reasoned there was no factual support for the doctor's opinion that the blood clot originated at the wound site, such as evidence from an autopsy, a relationship between the victim's death and the defendant's acts, or "explanations of the reasons underlying the cause of death." Brown, 57 Ill. App. 3d at 533. Without such facts, the relationship between the defendant's actions and the victim's death was purely speculative. Brown, 57 Ill. App. 3d at 532.