Principles of criminal sentencing in Tennessee: When there is a challenge to the length, range, or manner of the service of a sentence for an offense other than first degree murder, it is the duty of this court to conduct a de novo review with a presumption that the determinations made by the trial court are correct. Tenn. Code Ann. 40-35-401(d). This presumption is "conditioned upon the affirmative showing in the record that the trial court considered the sentencing principles and all relevant facts and circumstances." State v. Ashby, 823 S.W.2d 166, 169 (Tenn. 1991); see State v. Jones, 883 S.W.2d 597 (Tenn. 1994). The Sentencing Commission Comments provide that the burden is on the defendant to show the impropriety of the sentence. If the trial court followed the statutory sentencing procedure, made findings of fact that are adequately supported in the record, and gave due consideration and proper weight to the factors and principles that are relevant to sentencing under the 1989 Sentencing Act, we may not disturb the sentence even if a different result were preferred. State v. Fletcher, 805 S.W.2d 785, 789 (Tenn. Crim. App. 1991). Our review requires an analysis of: (1) the evidence, if any, received at the trial and sentencing hearing; (2) the presentence report; (3) the principles of sentencing and the arguments of counsel relative to sentencing alternatives; (4) the nature and characteristics of the offense; (5) any mitigating or enhancing factors; (6) any statements made by the defendant on his own behalf; (7) the defendant's potential for rehabilitation or treatment. Tenn. Code Ann. 40-35-102, -103, and -210; State v. Smith, 735 S.W.2d 859, 863 (Tenn. Crim. App. 1987). In calculating the sentence for a conviction for a felony committed before July 1, 1995, the presumptive sentence is the minimum within the range if there are no enhancement or mitigating factors. Tenn. Code Ann. 40-35-210(c) (1990) (amended July 1, 1995, to provide that the presumptive sentence for a Class a felony is the midpoint in the range). If there are enhancement factors but no mitigating factors, the trial court may set the sentence above the minimum. Tenn. Code Ann. 40-35-210(d). A sentence involving both enhancement and mitigating factors requires an assignment of relative weight for the enhancement factors as a means of increasing the sentence. Tenn. Code Ann. 40-35-210. The sentence may then be reduced within the range by any weight assigned to the mitigating factors presented. Before the enactment of the Criminal Sentencing Reform Act of 1989, the limited classifications for the imposition of consecutive sentences were set out in Gray v. State, 538 S.W.2d 391, 393 (Tenn. 1976). In that case, our supreme court ruled that aggravating circumstances must be present before placement in any one of the classifications. Later, in State v. Taylor, 739 S.W.2d 227 (Tenn. 1987), the court established an additional category for those defendants convicted of two or more statutory offenses involving sexual abuse of minors. There were, however, additional words of caution: Consecutive sentences should not routinely be imposed . . . and . . . the aggregate maximum of consecutive terms must be reasonably related to the severity of the offenses involved. 739 S.W.2d at 230. the Sentencing Commission Comments adopted the cautionary language. Tenn. Code Ann. 40-35-115. The 1989 act is, in essence, the codification of the holdings in Gray and Taylor; consecutive sentences may be imposed in the discretion of the trial court only upon a determination that one or more of the following criteria exist: (1) the defendant is a professional criminal who has knowingly devoted himself to criminal acts as a major source of livelihood; (2) the defendant is an offender whose record of criminal activity is extensive; (3) the defendant is a dangerous mentally abnormal person so declared by a competent psychiatrist who concludes as a result of an investigation prior to sentencing that the defendant's criminal conduct has been characterized by a pattern of repetitive or compulsive behavior with heedless indifference to consequences; (4) the defendant is a dangerous offender whose behavior indicates little or no regard for human life, and no hesitation about committing a crime in which the risk to human life is high; (5) the defendant is convicted of two (2) or more statutory offenses involving sexual abuse of a minor with consideration of the aggravating circumstances arising from the relationship between the defendant and victim or victims, the time span of defendant's undetected sexual activity, the nature and scope of the sexual acts and the extent of the residual, physical, and mental damage to the victim or victims; (6) the defendant is sentenced for an offense committed while on probation; or (7) the defendant is sentenced for criminal contempt. Tenn. Code Ann. 40-35-115(b). The length of the sentence, when consecutive in nature, must be "justly deserved in relation to the seriousness of the offense," Tenn. Code Ann. 40-35-102(1), and "no greater than that deserved" under the circumstances, Tenn. Code Ann. 40-35-103(2); State v. Lane, 3 S.W.3d 456 (Tenn. 1999). In Gray, our supreme court ruled that before consecutive sentencing could be imposed upon the dangerous offender, considered the most subjective of the classifications and the most difficult to apply, other conditions must be present: (a) that the crimes involved aggravating circumstances; (b) that consecutive sentences are a necessary means to protect the public from the defendant; (c) that the term reasonably relates to the severity of the offenses. In State v. Wilkerson, 905 S.W.2d 933, 938 (Tenn. 1995), our high court reaffirmed those principles, holding that consecutive sentences cannot be required of the dangerous offender "unless the terms reasonably relate to the severity of the offenses committed and are necessary in order to protect the public (society) from further criminal acts by those persons who resort to aggravated criminal conduct." The Wilkerson decision, which modified somewhat the strict factual guidelines for consecutive sentencing adopted in State v. Woods, 814 S.W.2d 378, 380 (Tenn. Crim. App. 1991), described sentencing as a "human process that neither can nor should be reduced to a set of fixed and mechanical rules." Wilkerson, 905 S.W.2d at 938.