Just finished reading the novel and her character as described on the novel called for a much tougher looking babe than J Lo. Back in those days, they could have gone for a Linda Fiorentino-type, or even better : Joanna Cassidy, but Jay-Lo ... Nahhh ... Didn't believe for a second that she could be a tough US Marshall ...
I really like this movie and I really like J-Lo in it too. But I have to agree that her level of toughness doesn't match up with what she is expected to do.
Can you imagine entering that house near the end without back-up? She is in Detroit in mid-winter without a warm coat too. Unprepared.
Lopez was perfectly cast here and excelled in a film that's nigh-on perfect in every area. No matter what Clooney, Lopez or Soderbergh have or will go on to achieve in the movies, this film will always be a highlight and works so well because of every ingredient.
I agree she was miscast, but mostly because there was zero chemistry between her and Clooney. Her accent and demeanor is just too urban to fit with Clooney, I felt nothing between them.
I think Jlo did a good job in this and thank good they didnt choose Sandra B, cause she could never ever play a tough cop in her life and she cant play much of anything either...only roles she can manage is retarded bimbo stalkin chicks, like in All about Steve...she is worthless, but Jlo did a fine job, im very satisfied with her in this movie as Karen Sisco. I also thinks she had an awsome chemistry with Clooney...i totally buyed their "in and out" relationship.