Set in April of 2020, Parker (Gideon Adlon) is showing being administered a rapid COVID test. The first rapid COVID tests were not available until May of 2020, and these were only available in healthcare settings. The first in-home rapid COVID tests were not available to the public until December of 2020. While it is possible that the killers took one from the hospital, a direct-read test that did not require laboratory equipment was not available until August of 2020.