Drug-cartel members may not be responsible after all for the five bodies found Saturday in a burnt vehicle in the desert of western Pinal County.

Tempe police said Tuesday they think the five were the members of a missing family from that Phoenix suburb, and that they were victims of a murder-suicide. The Pima County Medical Examiner's office, which is conducting autopsies on the bodies, has not identified them yet and will need to check dental records first.

But Tempe police were certain enough that a spokesman, Sgt. Jeff Glover, said investigators aren't looking for the missing Butwin family and believe there are no outstanding suspects in their disappearance.

An acquaintance of the Butwin family told police on Monday that he was concerned about them after receiving a note from James Butwin with instructions on how to operate his construction business without him, Tempe police Sgt. Jeff Glover said. Investigators went to the Butwin home and found "suspicious and concerning" evidence, but not the Butwins, and began treating the case as a murder-suicide. The family's white Ford Expedition also was gone.

Police found out Tuesday morning that the burned SUV found in the desert west of Casa Grande is the Butwins' vehicle.

Pinal County Sheriff Paul Babeu has said since the discovery of the bodies Saturday that it was likely they were victims of drug-war violence, in part because the area where they were found has a lot of smuggling activity.

"Given all these indicators, you don't have to be a homicide detective to add up all this information," Babeu said Saturday. He added via Facebook, "The border is NOT more secure than ever Ms. Napolitano!" referring to Secretary of Homeland Security Janet Napolitano.

Even after Tempe police made the connection Tuesday, Pinal County investigators continued looking into the possibility that the five were victims of drug-war violence.

Sheriff's spokesman Tim Gaffney said in a news release that investigators received a tip Saturday from a man who said his brother-in-law had gone to the Vekol Valley to do something illegal in a vehicle like the one found burned. Gaffney also pointed to a press report quoting an anonymous U.S. Border Patrol official who speculated that the killings were a hit by a drug trafficker.

"My guess, he's an illegal, maybe a Zetas cartel member and he was doing a hit for the Zetas," said the anonymous source quoted by Gaffney.

The Sheriff's Office declined to answer any questions about the information in the news release or whether they thought one possibility was more likely than another.

Glover of the Tempe police said there was an impending divorce between James Butwin and his wife Yafit and that the couple was experiencing difficulties. Yafit filed for divorce in September and the process was ongoing.

He said two of their children were teenagers and one was a pre-teen, but did not have their exact ages.

Robert Kempton, a neighbor of the Butwins, told The Associated Press that the couple had confided in him about going through a divorce and that James Butwin was battling a brain tumor.

Kempton said that after chemotherapy, the tumor returned and that James said late last week that he was discouraged that treatment wasn't helping him.

He said the family had been planning a summer trip to Israel, Yafit Butwin's home country.

"I would have thought that they would have worked through this," Kempton said, referring to the divorce. "This is a big shock."

Pima County Medical Examiner Gregory Hess said Tuesday that if the victims were Arizona residents with dental records here, that would make identification much easier.

The Associated Press contributed to this story. Contact reporter Tim Steller at 807-8427 or tsteller@azstarnet.com