No, intent not "ALWAYS" inferred. That is why there are different degrees of punishment for deaths: murder one, murder two, voluntary manslaughter, involuntary manslaughter, criminally negligent homicide...and on and on because not all deaths were the result of premeditated intent. And, sometimes, there is no intent at all for death, yet a death occurs, such as involuntary manslaughter and criminally negligent homicide.
Murderers often threaten people beforehand that they are going to kill them. Or, they keep a journal or a list of names. That is premeditated, and hasn't been proven here. Here they are trying to show the intent for SB transferred to CM...otherwise, there is no reason to even include SB in the testimony beyond that she went out with the group.
The witnesses were asked several times about EA's actions/feelings RE: SB because the prosecution must prove up their "jilted by SB, took it out on CM" theory that they used to get the grand jury to indict.
But, you are patently incorrect to assert that intent is "ALWAYS" inferred. Intent is sometime clear, sometimes not. And, sometimes, there is no intent at all and things go wrong. Criminal law is replete with examples of "crimes of passion" cases.
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