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, Denver-area media reported.
Police fired tear gas and entered the home after several hours of failed negotiations with the gunman, who had barricaded himself inside, and shot him dead, KUSA television reported. Inside they found three other people shot dead, media reports said.
The victims were believed to be related to the gunman, the Denver Post reported, citing Aurora police spokeswoman Cassidee Carlson.
Police reached by telephone in Aurora offered no immediate information on the situation.
Police notified neighbors of an emergency around 3 a.m. (1000 GMT) and evacuated several blocks, Carlson told KUSA.
One person inside had escaped and alerted authorities, KUSA said.
The gunman fired on a police vehicle around 8 a.m., leading to an exchange of gunfire, KMGH television said. At that time police saw a lifeless body for the first time.
The Denver suburb of Aurora was rocked by the mass shooting in July that had been the deadliest in the United States of 2012 until the December 14 massacre at an elementary school in Newtown, Connecticut, that killed 28 including the gunman.
In Aurora, a shooter opened fire during a midnight screening of the Batman movie "The Dark Knight Rises." Police identified former neuroscience graduate student James Holmes as the suspect in a crime that renewed debate about the sale of powerful semi-automatic rifles and extended capacity magazines.
(Reporting by Daniel Trotta; Editing by Vicki Allen and Will Dunham)