MOST JURISDICTIONS HAVE STATUTORILY DIVIDED MURDER INTO TWO OR MORE DEGREES: MURDER IN THE FIRST DEGREE, WHICH USUALLY REQUIRES PREMEDITATION AND DELIBERATION; AND MURDER IN THE SECOND DEGREE, WHICH IS UNPLANNED OR IMPULSIVE, BUT AN INTENTIONAL HOMICIDE DONE WITH MALICE AFORETHOUGHT. THE STATE HAS THE BURDEN OF ESTABLISHING THE CORPUS DELICTI: IT MUST PROVE THAT THE PERSON'S LIFE WAS FELONIOUSLY TAKEN AND THAT THE CRIMINAL AGENCY OF ANOTHER PERSON WAS THE CAUSE OF DEATH. IN SOME JURISDICTIONS, THE IDENTIY OF THE SLAIN INDIVIDUAL MUST ALSO BE ESTABLISHED. THE COMMON LAW MENS REA, OR CRIMINAL INTENT, OF MURDER IS MALICE AFORETHOUGHT: A FIXED PURPOSE TO KILL ANOTHER WHICH EXISTS PRIOR TO THE ACT. THE STATUTORY MENS REA IS A DESIGN TO EFFECT DEATH. THE LAW DOES NOT SPECIFY THE LENGTH OF TIME BETWEEN THE FORMING OF INTENT AND THE COMMISSION OF THE HOMICIDE. THIS VARIES AMONG COURTS, ALTHOUGH THE LENGTH OF TIME MUST BE SUFFICIENT TO ADMIT SOME REFLECTION AND DELIBERATION. PREMEDITATION USUALLY REFERS TO PLANNING THE PURPOSE AND DESIGN TO KILL PRIOR TO COMMISSION OF THE ACT, WHILE DELIBERATION USUALLY REQUIRES THAT THE ACT BE COMMITTED IN A COOL STATE OF BLOOD AND IN FURTHERANCE OF A FIXED DESIGN TO KILL. THE DOCTRINE OF TRANSFERRED INTENT APPLIES TO THE ACCIDENTAL KILLING OF ANOTHER PERSON IN THE FURTHERANCE OF A DESIGN TO KILL. IN MOST CASES, THE MENS REA WHICH THE SLAYER HAD FOR THE INTENDED VICTIM CARRIES OVER TO THE UNINTENDED VICTIM. HOMICIDE IS THE KILLING OF ONE PERSON BY ANOTHER, AND THE DEATH MUST OCCUR WITHIN 1 YEAR OF THE ACT ALLEGED TO BE THE CAUSE OF DEATH. EUTHANASIA IS CONSIDERED PREMEDITATED MURDER, AND MORE THAN ONE PERSON MAY BE GUILTY OF MURDER. IN CASES OF ACCIDENT, MISADVANTAGE, OR SELF-DEFENSE, THE HOMICIDE MAY BE FOUND TO BE EXCUSABLE OR JUSTIFIABLE. IN ALL JURISDICTIONS, LEGAL INSANITY AT THE TIME OF THE MURDER IS A COMPLETE DEFENSE TO A CHARGE OF PREMEDITATED MURDER. DIMINISHED MENTAL CAPACITY AND VOLUNTARY INTOXICATION MAY BE GROUNDS FOR A CHARGE OF SECOND- RATHER THAN FIRST-DEGREE MURDER. INSANITY CAUSED BY CHRONIC ALCHOLISM, ALCOHOLIC PSYCHOSIS, OR DELIRIUM TREMENS WOULD BE TREATED AS A FORM OF LEGAL INSANITY. VOLUNTARY MANSLAUGHTER IS AN OFFENSE DISTINCT FROM MURDER UNDER COMMON LAW AND MOST STATUTORY LAW. IT IS HOMICIDE WHICH, ALTHOUGH INTENTIONAL, IS COMMITTED UNDER THE INFLUENCE OF PASSION OR IN THE HEAT OF BLOOD, AND PRODUCED BY AN ADEQUATE, REASONABLE PROVOCATION; AT THE TIME OF THE ACT, REASON MUST BE OBSCURED TO AN EXTENT WHICH WOULD RENDER AN ORDINARY PERSON UNABLE TO ACT WITH REFLECTION OR DELIBERATION. THE BURDEN OF PROVIDING ALL ELEMENTS OF A CRIME BEYOND REASONABLE DOUBT REST SOLELY ON THE PROSECUTION. CIRCUMSTANTIAL EVIDENCE IS PARTICULARLY IMPORTANT IN PROVING INTENT AND MALICE AFORETHOUGHT. TO BE ADMISSIBLE IT MUST LEAD TO A REASONABLE INFERENCE, NOT MERELY A SUSPICION, OF THE FACT TO BE PROVED. NOTES AND REFERENCES ARE PROVIDED.(JAP)