Lyric discussion by PinkSpider304 

Cover art for Jane Doe lyrics by Within Temptation

I agree on a murderer revealing too much to someone he loves and then she mocks him and teases him about it. He needs to kill her before she finds out the truth, that it wasn't all jokes, this was real.

Sacrificed just her life for a higher love

The higher love for me sorta reflects his passion for the kill. Murderers find some sort of fascination with what they do. So his higher love is to murder and unfortunately it overpowers his desire for her life and he gets rid of her. And now he is going mad-sorta like the main character from Edgar Allen Poe's The Tell-a-Tale Heart where he keeps thinking the dead mans heart is beating. It's just him going crazy with guilt over the murder. This girl was obviously very precious to him.