She ran up large debts on credit cards in her parents’ names and after their deaths she continued to spend their pensions.
Essex Police said documents at the couple’s home “built a picture of a woman who was trying desperately to keep her parents from discovering the depth of the financial black hole she continued to dig, while giving them false assurances about her employment and future prospects”.
McCollough, who previously admitted two counts of murder, was sentenced at Chelmsford Crown Court but she showed no emotion as she was sent down.
Det Supt Rob Kirby, head of major crime at Essex Police, said the case had “shocked and horrified” even the force’s most experienced murder detectives.
He said McCullough had created a web of lies “on a shocking and monumental scale” and described her as “an intelligent and adept manipulator”.
A missing persons’ investigation was launched in September 2023 after Mr and Mrs McCullough’s GP raised concerns about not hearing from them.
Police became suspicious of the couple’s daughter due to her constant excuses for her parents whereabouts and later executed a warrant at the family home.
