Police on Tuesday claimed the gunman, who shot his six relatives dead before shooting self at a family Christmas gathering in Texas, was dressed as Santa Claus.
"The shooter showed up in the costume shortly before gunfire when the family appeared to have been opening Christmas presents," said Sgt. Robert Eberling, spokesperson of Grapevine police.
Seven persons, including three women, were found dead in a Texas apartment in the US on Christmas Day in a suburb of Fortworth, Grapevine in Texas.
The deceased, aged between 18 and 60, were found with gunshot wounds near a Christmas tree at the Lincoln Vineyard apartment's living room.
Investigators do not know what prompted the 56-year-old man to take such an extreme step.
Police said that victims were related by blood or marriage but all of them did not live in the apartment.
"We're getting a clearer picture, but we're not ready to go on the record with anything until we find out from the medical examiner absolute confirmation of identities and the manner of death," Eberling said.
Eberling called it "a tragic situation," and one of the most gruesome crimes in Grapevine history. The Dallas suburb is about 32km from downtown and known to be a quiet, middle-class community.
Neighbours at the well-maintained suburban apartment complex did not report hearing any gunshots during the killing spree however some area residents said many of the nearby apartments were vacant.
Otherwise a quiet suburb, Grapevine, is considered as the "Christmas Capital of Texas", because of the holiday décor as the city becomes blanketed with millions of lights, enormous decorations, animated characters and a whole lot more.