“48 Hours” goes behind the scenes with a defense team and cutting edge forensic animators as they strategize to defend a woman accused of murder. CBS News correspondent Tracy Smith investigates in a special two-hour edition of “48 Hours” airing Saturday, Dec. 23 starting at 9 p.m. ET/PT on CBS.

Honoring the victim: Robert McKernan.

Related Links:
Sneak peek: The Evidence Room | 48 Hours
“It was the last time he was going to hurt me” | 48 Hours
Colleen McKernan reaches plea deal, avoids third murder trial
Air Force Veteran Colleen McKernan Shot Husband Robert 10 Times; Plead Guilty to Manslaughter to Avoid 3rd Trial, Sentenced to 7 Years in Prison (2014)