Prediction: it was probably a hit from an X26 Taser, with a transcardiac vector.
A 25-year old Sultan man is dead after a Taser shock during an encounter with Snohomish County sheriff's deputies. ... After the man was hit, the deputies found he wasn't breathing. They began CPR and called for medical aid. The man was taken to a hospital but could not be revived. This is the second time in a week that a man has died in Western Washington after being shocked by a Taser. A 27-year-old stopped breathing in Spanaway on Tuesday during an encounter with Pierce County police.[LINK]
Conclusion: tasers can kill.
Anyone that denies this obvious fact is either ill-informed, misled or an evil liar.