Reuters is reporting that the guards did not follow procedures for some reason.

https://www.reuters.com/article/us-people-jeffrey-epstein/disgraced-money-manager-jeffrey-epstein-dead-in-apparent-suicide-idUSKCN1V00GM

Excerpt: At the MCC, two jail guards are required to make separate checks on all prisoners every 30 minutes, but that procedure was not followed overnight, according to the source. In addition, every 15 minutes guards are required to make another check on prisoners who are on suicide watch.