A statute in the jurisdiction defines murder in the first degree as knowingly killing another person after deliberation. Deliberation is defined as "cool reflection for any length of time no matter how brief." Murder in the second degree is defined as "all other murder at common law except felony-murder." Felony-murder is murder in the third degree. Manslaughter is defined by the common law. At 2 a.m., Duncan held up an all-night liquor store using an assault rifle. During the holdup, two police cars with flashing lights drove up in front of the store. In order to create a situation where the police would hesitate to come into the store (and thus give Duncan a chance to escape out the back) Duncan fired several rounds through the front window of the store. Duncan then ran out the back but upon discovering another police car there, surrendered quietly. One of the shots he fired while in the store struck and killed a burglar who was stealing items from a closed store across the street. The most serious degree of criminal homicide Duncan is guilty of is 
murder in the first degree. murder in the second degree. murder in the third degree. manslaughter.