He's an attempted murderer until she dies. Then he's a murderer.
You might want to pull out your copy of Black’s Law Dictionary and look up the definition of “murder”. To save you time, here it is:
"Murder is the crime of intentionally causing the death of another human being, without lawful excuse. When an illegal death was not caused intentionally, but was caused by negligence (or some other defense, such as diminished capacity), the crime committed is manslaughter, which is considered to be less serious than murder. Manslaughter is often broken into two categories: involuntary manslaughter and voluntary manslaughter."
Please note – “…without lawful excuse.” That means an illegal act, and does not apply in this case.