(1) The Court shall not impose sentence without first ordering a pre-sentence investigation of the defendant and according due consideration to a written report of such investigation where:

    (a) the defendant has been convicted of a felony;  or

    (b) the defendant is less than twenty-two years of age and has been convicted of a crime;  or

    (c) the defendant will be [placed on probation or] sentenced to imprisonment for an extended term.

  (2) The Court may order a pre-sentence investigation in any other case.

  (3) The pre-sentence investigation shall include an analysis of the circumstances attending the commission of the crime, the defendant's history of delinquency or criminality, physical and mental condition, family situation and background, economic status, education, occupation and personal habits and any other matters that the probation officer deems relevant or the Court directs to be included.

  (4) Before imposing sentence, the Court may order the defendant to submit to psychiatric observation and examination for a period of not exceeding sixty days or such longer period as the Court determines to be necessary for the purpose.  The defendant may be remanded for this purpose to any available clinic or mental hospital or the Court may appoint a qualified psychiatrist to make the examination.  The report of the examination shall be submitted to the Court.

  (5) Before imposing sentence, the Court shall advise the defendant or his counsel of the factual contents and the conclusions of any pre-sentence investigation or psychiatric examination and afford fair opportunity, if the defendant so requests, to controvert them.  The sources of confidential information need not, however, be disclosed.

  (6) The Court shall not impose a sentence of imprisonment for an extended term unless the ground therefor has been established at a hearing after the conviction of the defendant and on written notice to him of the ground proposed.  Subject to the limitation of Subsection (5) of this Section, the defendant shall have the right to hear and controvert the evidence against him and to offer evidence upon the issue.

  (7) If the defendant is sentenced to imprisonment, a copy of the report of any pre-sentence investigation or psychiatric examination shall be transmitted forthwith to the Department of Correction [or other state department or agency] or, when the defendant is committed to the custody of a specific institution, to such institution.