David King

David King testified for the prosecution on Day 51 of the penalty phase as a Massachusetts General Hospital trauma surgeon experienced in treating explosive-device injuries. Under Nadine Pellegrini's questioning, he described responding to the hospital after the bombings and personally examining three patients. Their traumatic amputations, burns and fragmentation wounds were consistent with an improvised explosive device. He distinguished those patients from the emergency department's total patient population, which he did not know when he arrived.

King explained the immediate danger of hemorrhage and the difficulty of controlling bleeding from junctional wounds that cannot be treated with a limb tourniquet. One patient's continuing blood loss made him fear imminent death. He testified that fatal blood loss generally develops over time rather than instantaneously, and that controlling bleeding does not end the risks from transfusions, infection, organ failure, anesthesia and further operations. Attempts to salvage an injured limb could also endanger another limb used as a source of replacement blood vessels.

After the morning recess, King distinguished localized somatic pain from less localized visceral pain and explained why medication sufficient to eliminate severe pain can itself be dangerous. Based on his review of Henry Nields's autopsy report and findings, he testified with a high degree of medical certainty that Martin Richard died from rapid blood loss, not instantaneously. He said Richard's abdominal injuries would have caused both forms of pain and explained how smaller stature and a smaller aorta increased vulnerability to blast injury and blood loss. The defense asked no questions, and King was excused.

Before King testified, the defense sought to exclude his testimony, arguing that his military background risked prejudice and that detailed accounts of surviving victims' injuries did not establish the asserted aggravating factors. The prosecution argued that his trauma experience supported opinions about grave risk of death, pain and Richard's vulnerability. The court denied exclusion but limited military background and barred an extended marathon-day story. During direct examination, it allowed a deployment answer over a renewed objection and let an injury-pattern answer stand, while asking counsel to heed the defense's concern about narrative testimony.