Examining the effect of case and trial factors on defense attorneys’ plea decision-making

ABSTRACT

Defense attorneys are attuned to the defendant’s likelihood of conviction at trial, based on the strength of the evidence, in forming their plea decisions. A higher threshold for conviction (i.e. unanimous jury verdict rule versus majority rule), could affect defense attorneys’ willingness to take cases to trial. In this study, we examined defense attorney decision-making by presenting defense attorneys with a hypothetical case summary in which the jury verdict rule was unanimous versus majority rule (experiment one, N = 82), and the strength of the evidence was weak versus strong (experiment two, N = 81). In experiment one, there was no direct or indirect effect of jury verdict rule on plea decision-making. Rather, defense attorney estimates of the defendant’s likelihood of conviction predicted plea decisions; defense attorneys who perceived a higher likelihood of conviction were more likely to recommend plea bargaining than those who perceived a lower likelihood of conviction. In experiment two, strength of evidence influenced a number of defense attorney decisions. Defense attorneys in strong evidence conditions were more likely to recommend plea bargaining, rated the defendant’s likelihood of conviction higher, and their probability of winning at trial lower than those in weak evidence conditions.

KEYWORDS:

• Plea bargaining
• jury verdict rule
• strength of evidence
• defense attorneys
• Shadow of trial

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that supports the findings of this study are available from the corresponding author, upon reasonable request.

Notes

1 We conducted these same analyses excluding those who failed the jury verdict manipulation check (N = 10). The results were consistent with those presented here.

2 We conducted the planned analyses for this experiment a second time excluding those who failed the jury verdict manipulation check question (N = 10) Additionally, two participants did not answer this question. The results from this data set were consistent with the results presented here with one exception. In examining the effect of strength of evidence on defense attorneys’ perceptions of the defendant’s actual guilt, the not significant effect (reported in the text) became significant (t (66) = -2.49, p = .015). Defense attorneys in strong evidence conditions rated the defendant’s actual guilt higher (M = 4.00, SD = 0.48) than those in weak evidence conditions (M = 3.63, SD = 0.73).

Additional information

Funding

This study was supported by an American Psychology-Law Society Early Career Professional grant.