Doug Gustafson was a young hellraiser whose prank ended up killing an innocent teen. That was only the beginning for the killer Gustafson siblings, though.
Jamie Weast said she knew her brother James "Jim" Cappello was suspicious his wife, Marjorie Nicole “Nikki” Cappello, may have been using drugs, but she didn't think the woman would be capable of murder.
Pablo Colon shot his wife Sandra Colon, mother-in-law Olga Alvarez and one of his twin daughters, but the second daughter was miraculously found alive.
Parts of Maria Agnes Cuevas-Garcia's body, stuffed inside a suitcase and thrown in a dumpster by a car wash, made one person do a double take. They were unsure if they were seeing a body or a Halloween decoration.
Perhaps the most infamous killer siblings in modern history, Lyle and Erik Menendez blasted their parents so many times with a shotgun they were unrecognizable.
"The evidence, to me, suggests that there was a level of premeditation, that her death was violent, it did not have to happen and that there was a great deal to cover up that death," Jacksonville Sheriff’s Office Det. Neil Chandler testified in court about Logan Mott's killing of grandmother Kristina French.
Kelly Renee Turner is accused of lying about the medical conditions of two of her three daughters—even withdrawing medical care and nourishment in the final weeks of her daughter Olivia’s life despite the insistence of at least one doctor who said she did not have a terminal illness.