Eichenwald, a contributing editor at Vanity Fair and a senior writer at Newsweek, first said in December that a Twitter troll sent him a flashing video with the message, "you deserve a seizure," which triggered an epileptic episode.
He received the tweet after appearing on Fox News show Tucker Carlson Tonight, where he and the host argued about each other's biases and Eichenwald's coverage of Donald Trump during the presidential campaign.
According to a criminal complaint, messages sent from Rivello's Twitter account mentioned Eichenwald, saying "I know he has epilepsy," "I hope this sends him into a seizure" and "let's see if he dies."
Authorities also found an screenshot of Eichenwald's Wikipedia page on Rivello's iCloud account, the criminal complaint said, altered to list his date of death as Dec. 16, 2016. Other files on the iCloud account include a list of things that trigger epileptic seizures and a screenshot of a Dallas Observer article about Eichenwald's attempts to find the person who tweeted at him.