(1) When the court is of the opinion that imprisonment may be appropriate but desires more detailed information as a basis for determining the sentence to be imposed than has been provided by the presentence report required by section 29-2261, the court shall commit an offender to the Department of Correctional Services for a period not exceeding ninety days. The department shall conduct a complete study of the offender during that time, inquiring into such matters as his or her previous delinquency or criminal experience, social background, capabilities, and mental, emotional, and physical health and the rehabilitative resources or programs which may be available to suit his or her needs.

(2) By the expiration of the period of commitment or by the expiration of such additional time as the court shall grant, not exceeding a further period of ninety days, the offender shall be returned to the court for sentencing and the court shall be provided with a written report of the results of the study, including whatever recommendations the department believes will be helpful to a proper resolution of the case. After receiving the report and the recommendations, the court shall proceed to sentence the offender in accordance with section 29-2204 or 29-2204.02. The term of the sentence shall run from the date of original commitment under this section.

(3) In order to encourage the use of this procedure in appropriate cases, all costs incurred during the period the defendant is held in a state institution under this section shall be a responsibility of the state and the county shall be liable only for the cost of delivering the defendant to the institution and the cost of returning him or her to the appropriate court for sentencing or such other disposition as the court may then deem appropriate.