Four people were dead, including the gunman, following a hostage-taking incident on Saturday in Aurora, Colorado, the same town where a man shot dead 12 people and wounded 58 more at a movie theater last July, KUSA television reported.
Police entered the home after several hours of failed negotiations with the gunman, who had barricaded himself inside, and shot him dead, the television news reported. Inside they found three other people shot dead, KUSA reported.
Police reached by telephone in Aurora offered no immediate information on the situation. Police notified neighbours of an emergency around 3 am (1000 GMT) and evacuated several blocks, Aurora police spokeswoman Cassidee Carlson told KUSA.
One person inside had escaped and alerted authorities, KUSA said.
The US was shaken last month when a gunman barged into an elementary school and shot dead 20 little children and six school staffers, in one of a series of such shooting incidents that has sparked a gun control debate in the country.
(Reporting by Daniel Trotta)