Montana Title 46. Criminal Procedure § 46-18-219. Life sentence without possibility of release

(1)(a) Except as provided in subsection (3), if an offender convicted of one of the following offenses was previously convicted of one of the following offenses or of an offense under the laws of another state or of the United States that, if committed in this state, would be one of the following offenses, the offender must be sentenced to life in prison, unless the death penalty is applicable and imposed:

(b) Except as provided in subsection (3), if an offender convicted of one of the following offenses was previously convicted of two of the following offenses, two of any combination of the offenses listed in subsection (1)(a) or the following offenses, or two of any offenses under the laws of another state or of the United States that, if committed in this state, would be one of the offenses listed in subsection (1)(a) or this subsection, the offender must be sentenced to life in prison, unless the death penalty is applicable and imposed:

(a) shall serve the entire sentence;

(b) shall serve the sentence in prison;

(c) may not for any reason, except a medical reason, be transferred for any length of time to another type of institution, facility, or program;

(d) may not be paroled; and

(e) may not be given time off for good behavior or otherwise be given an early release for any reason.

(5)(a) For purposes of this section, “prison” means a secure detention facility in which inmates are locked up 24 hours a day and that is operated by this state, another state, the federal government, or a private contractor.

(b) Prison does not include a work release center, prerelease center, boot camp, or any other type of facility that does not provide secure detention.