Since Zelich stated he killed Laura in the hotel in Minnesota I started looking at their statutes. From what I gather, he could be charged with first degree murder. Depending on how he says the events took place, it appears the crime could fall under the 2nd listing for murder in the first.
609.185 Murder in the First Degree
(a) Whoever does any of the following is guilty of murder in the first degree and shall be sentenced to imprisonment for life:
(2) causes the death of a human being while committing or attempting to commit
criminal sexual conduct (see 609.343) in the first or
second degree with force or violence* either upon or affecting the person or another;
609.343 Criminal Sexual Conduct in the Second Degree
A person who engages in sexual contact with another person is guilty of criminal sexual conduct in the second degree if any of the following circumstances exists:
(e) the actor causes personal injury
** to the complainant, and either of the following circumstances exist:
(ii) the actor knows or has reason to know that the complainant is mentally impaired, mentally incapacitated, or physically helpless
***;
Also listed at the end of this statute "Neither mistake as to the complainant's age nor consent to the act by the complainant is a defense."
My reasons for thinking the above:
* Violent because due to his actions one person had already died in a like-manner; thus, it is absolutely within reason for him to know the possible outcome.
** Laura had to have been injured prior to death, scientifically speaking.
*** My understanding is Laura was bound/gagged, rendering her physically helpless.
I'm not a lawyer and I don't know all the legalities behind statutes so I could be off. However, I did try to fully understand the exact meanings behind the statutes I've listed as well as read all the definitions of 'this-means-this' before posting my opinion.
Minnesota Statutes -
https://www.revisor.mn.gov/statutes