There is no rule as to how victims of sexual assault are apt to behave.
A trial judge makes a fatal error in reasoning when that judge bases findings of credibility on assumptions that are unsupported by the evidence.
It is an error of law to rely on pre-conceived views about how a sexual assault victim would behave.
R. v. D.D., 2000 SCC 43 (CanLII),  2 S.C.R. 275 at para. 65;
R. v. A.R.J.D., 2018 SCC 6 (CanLII),  1 S.C.R. 218, at para. 2.
Although trial judges must exercise common sense when making credibility findings and resolving what actually happened in a case, relying upon assumptions about what women will and will not do may impact a judge’s objective deliberation of the reasonable doubt standard.
R. v. J.L., 2018 ONCA 756 (CanLII), at para. 47: where the trial judge improperly relied on a behavioural assumption in assessing credibility, viz: “I cannot accept that a young woman would go outside wearing a dress in mid-December, lie down in dirt, gravel and wet grass and engage in consensual sexual activity.”
See also R. v. Mah, 2002 NSCA 99 (CanLII),  N.S.J. No. 349, at para. 75, per Cromwell J.A. (as he then was).
Reliance on stereotypical assumptions is not always immediately obvious. Sometimes the impermissible use of stereotypes is opaque, cloaked with the faux imprimatur of common sense.
See R. v. A.B.A. 2019 ONCA 124 (CanLII), 372 C.C.C. (3d) 301, at para. 7.
To suggest that stereotypical thinking is merely logic or common sense is a licence for it to continue unmasked and unabated.
R. v A.R.D., 2017 ABCA 237 (CanLII), at para. 9 (per Paperny and Schutz JJ.A).
Among others, the following have been found to be impermissible stereotypes about sexual assault victims:
R. v. Kiss, 2018 ONCA 184 (CanLII), at para. 101.
*That a victim of a sexual assault will leave or attempt to leave the assault.
R. v. Lacombe, 2019 ONCA 938, at para. 45.
*That child sexual assault survivors will demonstrate avoidant behaviour in relation to their sexual perpetrators.
R. v A.R.D., 2017 ABCA 237 (CanLII), at para. 47 (aff’d R. v. A.R.J.D., 2018 SCC 6).
*That a victim of domestic assault will contact or cooperate with police if she had been assaulted.
R. v. Sadeghpour, 2019 ONCJ 477, at para. 13.
Historically, general assumptions about human behaviour have operated to undermine a complainant’s testimony. But they may also operate in the reverse to undermine the accused’s credibility and artificially bolster a complainant’s credibility.
R. v. J.L., 2018 ONCA 756 (CanLII), 367 C.C.C. (3d) 249, at paras. 46-47.
In R. v. Cepic, 2019 ONCA 541, for instance, the trial judge’s path to conviction rested largely on a series of erroneous assumptions about what a young woman would or would not do in the when visiting a male strip club for the first time. These assumptions not only bolstered the complainant’s testimony, but also undermined the accused’s version of events.
Written by Stuart O’Connell, O’Connell Law Group, Toronto.