Police have confirmed the identity of the killer, while US media is reporting he was a white male who had been living in a retirement community.
Stephen Craig Paddock was a resident of Mesquite, Nevada, with no known terror connections.
The gunman was shot dead by authorities after he opened fire on the concert, killing more than 50 people and injuring over 200 others.
The incident has been confirmed as the deadliest mass shooting in US history, surpassing the Orlando shooting at the Pulse nightclub in June 2016 when 49 people were killed.