Renée Zellweger was "amazed" when she saw herself as murderer Pam Hupp for the first time after donning a body prosthetic.
The 52-year-old actress transformed into the killer - who is serving a life sentence for the 2016 murder of Louis Gumpenberger - for NBC true crime series 'The Thing About Pam', and the star insists it was "really important" for the viewers that she tried to look as much like Hupp as possible.
Speaking about seeing herself as Hupp for the first time, she said: "Amazement, I was amazed. You might achieve a couple of things, but I had no expectation it was gonna be as remarkable as that.
"The idea is to be accurate, the idea is accuracy. I think, especially in the case of telling this story, it was really important to as closely resemble Pam Hupp as we possibly could, because she seems so familiar, she seems like someone that we recognise, and we know.
"In order for you to better understand how possible it might be that people would project onto her who they are sure that she might be or what kind of person she might, it just seemed really important that we got as close to that as we could."
The series was mainly filmed in New Orleans, where it was regularly hot and humid, but Renée found the make-up process "amazing to watch".
She added to 'Entertainment Tonight': "It was hot. It was really hot. But it's amazing to watch.
"Arian, who builds these things and applies them every day, he creates them by hand and paints them down to the last freckle. His precision is remarkable. It's part of the adventure, watching that happen every day, is pretty cool."
The 'Bridget Jones's Diary' star revealed she was initially spending four hours being transformed into Hupp, but towards the end of filming it only took two hours.
She told E!: "We started at about four [hours] and we whittled it down to around two.
"They have a mind of their own, you know? If everybody cooperates - the cheeks are feeling like playing nice, the nose, and everything. But yeah, it took about a couple of hours."
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