A father who killed six family members in a Texas apartment on Christmas while dressed as Santa planned the crime, but didn't commit an "honor" killing, police said.

So far, Grapevine (Texas) Police investigators have uncovered no evidence supporting a theory that the crime was motivated by misplaced cultural pride, Sgt. Robert Eberling told POLICE Magazine.

"That was brought up early on, but we don't have anything [supporting that theory]," Eberling said Wednesday. "We don't believe that's what occurred here."

Aziz Yazdanpanah, who separated from his wife in March, killed six people including his wife and two children, before turning the gun on himself. The family had recently declared bankruptcy, and Aziz was squatting in their former foreclosed house. He was living in the house without power or water at the time of the attack.

Police said Yazdanpanah killed his wife, Fatemeh Rahmati, 55, their children Nona Yazdanpanah, 19, and Ali Yazdanpanah, 14, Rahmati's sister, Zohreh Rahmaty, 58; her husband, Mohamad Hossein "Cyrus" Zarei, 59; and their daughter, Sara Zarei, 22 before turning the gun on himself.

They all had gunshot wounds to the head and it appears they were killed in rapid succession. Cyrus Zarei was also shot in the chest and abdomen.

Investigators recovered two handguns (in .40-caliber and 9mm) from the scene and believe Yazdanpanah fired at least 25 rounds. Each victim was hit with rounds from both guns. One of the handguns was found near Zarei's body, indicating that Yazdanpanah may have tried to implicate his brother-in-law for the murders.

And because investigators found no suicide note, he probably didn't plan to kill himself until he realized what he had done, Sgt. Eberling said.

The crime scene presented a challenge for Grapevine Police personnel, who spent about eight hours processing the scene, after a several-hour holiday delay to obtain a search warrant from a judge. Several medical examiners from Tarrant County joined the department's four detectives and two technicians.

Investigators were careful to meticulously collect evidence and document their findings.

"Anytime you have a situation like this, it's always a good idea to slow your crime scene down and let the evidence answer some of these questions," Sgt. Eberling added.

By Paul Clinton