UnitedHealthcare is an operating division of UnitedHealth Group, the largest single health carrier in the United States.
www.uhc.com
An article I read said that police were looking to former disgruntled employees so I started researching who was CEO before Thompson (not that I think that person has anything to do with this) and it led me to the UHC website.
I do have to give kudos to whomever runs the UHC site because the 'Meet Our Executive Leadership' page leads you to somewhere else, I'm assuming to protect the identity of others...or it could have been a broken link for a while.