(at around 28 mins) When there is a POV shot from the killer in the account directors office there is a shelf full of board games. Some of them were released after the year the film takes place such as Finger Pointing (2013), and Krazy Karts (2016).
(at around 1h 50 mins) Towards the end of the film, Bob the cop has a Mortal Kombat logo tattooed on his forearm. Mortal Kombat (1992), the original game in this series, wouldn't be released until 1992, and the film takes place in the 1980's.
The nurse has numerous upper body tattoos, but tattoos were not en vogue for women in 1986. In fact, women during this era rarely had any tattoos.
(at around 59 mins) Though the film is set in the summer of 1984, the Sherriff quotes the film Rocky IV (1985) which wasn't released until November of 1985.