The Torah regards killing an unborn baby exactly the same way it does killing a nochri. A nochri who kills another nochri, whether born or not, or an unborn yisroel, is executed for it. A yisroel who does the same is not executed. Does that mean it’s not murder? You tell me. But whatever you say about killing an unborn baby you have to say the same about killing an adult nochri.
Also, if abortion were not murder we wouldn’t need to justify it when the mother’s life is in danger by invoking the law of a rodef. A baby who is attacking its mother and putting her life in danger is killed exactly like anyone else who is doing the same thing. If someone is pointing a gun at an innocent person and about to pull the trigger it doesn’t matter whether that person is 20 years old, 2 years old, or minus two months old.