Does 'mensrea' apply to abortion?

Alan Douglas: If you shoot what you think is a tree stump, and it turns out to be someone's head, are you guilty of murder? You caused their death but the law defines murder as requiring that you intended to kill them. That intent, called 'mensrea', is an essential element of the crime of murder. Without mensrea you are not guilty (responsible) for the crime of murder. You might be guilty of gross and reckless behavior as in manslaughter, etc.

Editor: If you rid yourself of what you think is a 'blob of cells' are you guilty of murder?