Factual error: Federal institutions have strict rules for inmates or patients based on the reason for their incarceration, including substituting metal utensils with safer plastic ones. Despite being convicted of brutally killing his family, Myers is still trusted with a sharp metal fork - resulting in the nurse's death.
Factual error: There's no way a body can be pinned to the wall with the tip of a butcher's knife.
Factual error: When Laurie, Annie, and Lynda are walking home from school on Oct 31st, you see the "fall" leaves on the ground, however the surrounding trees are as green as can be. (01:04:15 - 01:05:30)
Factual error: As Laurie, Linda and Annie are walking home after school, they pass several palm trees which are not typically found in Illinois.
Answer: He was hoping that Laurie would realise that she's really his sister. However, because Laurie was just a baby and raised by another family, she had no idea why Michael was showing her the picture or what it had to do with her.