GRAPEVINE, Texas — Authorities in suburban Dallas say they believe a 56-year-old man dressed as Santa Claus killed his estranged wife, his two teenage children and three others on Christmas Day before turning the gun on himself.

Grapevine police spokesman Robert Eberling said Tuesday that detectives believe Aziz Yazdanpanah's marital and financial troubles led him to kill his family.

The Tarrant County, Texas, medical examiner identified the others killed as his wife's sister, her daughter and her husband.

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.

It appeared they had been opening presents around their Christmas tree just before the attack.