the Supreme Court again emphasized the need for deference in
appellate review of sentence. LeBel J. observed, at paras. 14-15:
In its past decisions, this Court has established that appellate courts must
show great deference in reviewing decisions of trial judges where appeals
against sentence are concerned. An appellate court may not vary a sentence
simply because it would have ordered a different one. The court must be
“convinced it is not fit”, that is, “that . . . the sentence [is] clearly unrea-
sonable” (R. v. Shropshire,  4 S.C.R. 227, at para. 46, quoted in R. v.
McDonnell,  1 S.C.R. 948, at para. 15). This Court also made the follow-
ing comment in R. v. M. (C.A.),  1 S.C.R. 500, at para. 90:
. . . absent an error in principle, failure to consider a relevant factor, or
an overemphasis of the appropriate factors, a court of appeal should only
intervene to vary a sentence imposed at trial if the sentence is demon-
. . . . .
Owing to the profoundly contextual nature of the sentencing process, in
which the trier of fact has broad discretion, the standard of review to be
applied by an appellate court is one based on deference. The sentencing judge
has “served on the front lines of our criminal justice system” and possesses
unique qualifications in terms of experience and the ability to assess the submissions of the Crown and the offender (M. (C.A.), at para. 91). In sum, in the
case at bar, the Court of Appeal was required — for practical reasons, since the
trier of fact was in the best position to determine the appropriate sentence for
L.M. — to show deference to the sentence imposed by the trial judge.
 I will return to the issue of deference later in these reasons, when I consider the fitness of the sentence.
 I turn to another important principle applicable to this case.
Primacy of denunciation and deterrence in sentencing
adult sexual predators
 It has been stated time and again, often with reference to
this court’s decision in R. v. D. (D.) (2002), 58 O.R. (3d) 788,
 O.J. No. 1061, 163 C.C.C. (3d) 471 (C.A.), that in the sen-
tencing of adult sexual predators, the objectives of denunciation,
general and specific deterrence and the separation of offenders
from society must be paramount. In D. (D.), Moldaver J.A., as he
then was, stated, at paras. 33-35:
Before going further, I wish to emphasize that the ranges which I have iden-
tified are not meant to be fixed and inflexible. On the contrary, sentencing is
not an exact science and trial judges must retain the flexibility needed to do
justice in individual cases. The suggested ranges are merely guidelines
designed to assist trial judges in their difficult task of fashioning fit and just
sentences in similar cases.
The overall message however, is meant to be clear. Adult sexual predators
who would put the lives of innocent children at risk to satisfy their deviant
sexual needs must know that they will pay a heavy price. In cases such
as this, absent exceptional circumstances, the objectives of sentencing