I have to disagree with you there. Or suggest you define the termd “lawful” and “unlawful”.
After all, abortion is lawful in the secular sense.
I think it is important to be clear what the Church teaches regarding the fifth commandment:
2261 Scripture specifies the prohibition contained in the fifth commandment: “Do not slay the innocent and the righteous.” The deliberate murder of an innocent person is gravely contrary to the dignity of the human being, to the golden rule, and to the holiness of the Creator. the law forbidding it is universally valid: it obliges each and everyone, always and everywhere.
I suggest looking at these links for the distinction between innocent persons and those who are not innocent (unjust aggressors, war, peace, capital punishment, etc):
vatican.va/archive/ENG0015/__P7Z.HTM
vatican.va/archive/ENG0015/__P80.HTM
vatican.va/archive/ENG0015/__P81.HTM