Md. Code, Criminal Law § 2–203

A defendant found guilty of murder in the first degree may be sentenced to imprisonment for life without the possibility of parole only if:

(1) at least 30 days before trial, the State gave written notice to the defendant of the State’s intention to seek a sentence of imprisonment for life without the possibility of parole; and

(2) the sentence of imprisonment for life without the possibility of parole is imposed in accordance with § 2-304 of this title.