Police say the shooter, Aziz Yazdanpanah, dressed up as Santa and opened fire on the six victims just after they finished opening presents, killing his estranged wife, two teenage children, his wife's sister, her daughter and her husband. He then turned the gun on himself.
Police responding Sunday morning to a 911 call made without anyone on the line found the seven people inside an apartment near Dallas-Fort Worth International Airport.
Authorities said those killed were: Yazdanpanah, 56; Fatemah Rahmati, 55; Nona Yazdanpanah, 19; Ali Yazdanpanah, 14; Mohamad Hossein Zarei, 59; Zohreh Rahmaty, 58; and Sara Fatemeh Zarei, 22.
Detectives believe Yazdanpanah's marital and financial troubles led him to kill his family.
Yazdanpanah's wife filed for bankruptcy in August 2010, and she told her attorney she hoped the proceedings would stave off foreclosure of the home where the family had lived for more than a decade.
In the midst of the bankruptcy, she separated from Yazdanpanah and the proceedings were later dismissed because she failed to make the plan payments, said the attorney, George Barnes.
One of the victims of a Christmas Day shooting in Texas that left seven dead sent text messages before her uncle opened fire on the gathering saying he was there dressed as Santa Claus and wanting to be "all fatherly," police said Wednesday.
Yazdanpanah's niece, 22-year-old Sara Fatemeh Zarei, sent a text to a friend just before 11 a.m. saying they had arrived at the apartment and that Yazdanpanah was there. "Soo we're here. We just got here and my uncle is here too. Dressed as Santa. Awesome," she said in one text.
At 11:15 a.m. she texted, "Now he wants to be all fatherly and win father of the year."
The Associated Press contributed to this report.