The wording of the question is a bit overdramatic: it's not so much "is now a crime" as "is generally recognized by everyone connected with the legal profession as juror misconduct," and it was juror misconduct at the time of the film, too (filmmakers are generally not legal professionals, and are far more interested in making a gripping movie than in getting nuances of the law correct).
That said, early in the movie we find out that Juror #8 (Fonda) has conducted his own investigation into the case, which he should not have done; he has introduced unsworn testimoney (his own), which he should not have done; and he has introduced evidence through improper channels, which he should not have done. This is probably what you're thinking of.
There are further instances of judicial misconduct in the movie, but these are the ones that occur nearest the beginning.
The Fonda's. Henry in Twelve Angry Men", Jane in "Klute" and Peter in "Easy Rider".
from twelve angry men justice and fairness will prevail if there is one just man who believes in them
Mork and Mindy - 1978 Twelve Angry Appliances 3-12 is rated/received certificates of: Argentina:Atp
Henry Fonda
non guilty
Twelve Angry Months was created in 2007.
Juror Eight is the protagonist in Twelve Angry Men.
Dramatic Publishing http://www.dramaticpublishing.com/p1602/Twelve-Angry-Men/product_info.html
Lumet, S., & Rose, R. (1957). Twelve angry men. Los Angeles: Orion-Nova Twelve Angry Men.
The law is accurate in the movie Twelve Angry Men as it relates to finding a Defendant "Guilty beyond reasonable doubt."
The Fonda's. Henry in Twelve Angry Men", Jane in "Klute" and Peter in "Easy Rider".
The Great Defender - 1995 Twelve Angry Men 1-8 was released on: USA: 1995
from twelve angry men justice and fairness will prevail if there is one just man who believes in them
Mork and Mindy - 1978 Twelve Angry Appliances 3-12 is rated/received certificates of: Argentina:Atp
Henry Fonda
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