Officers went to her house near 3900 W. Blue Meadow Drive (5850 South) Wednesday morning after relatives said that they had not heard from her for several days. Officers found her body inside and immediately believed the death was suspicious. An autopsy concluded she had been suffocated.
There were no signs of forced entry, and it is possible that Quintanilla knew Steffey, Salt Lake County Sheriff Jim Winder said at a Saturday evening news conference. Investigators found fingerprints that places the man in "close proximity" to Steffey when she died, according to the arrest affidavit.
Also, Quintanilla was allegedly draining Steffey's ATM card following her death, Winder added. While police are still looking into those purchases, the sheriff said that some of them were for food and means to flee the country.
Police found Quintanilla about 7 a.m. Saturday with a 10 a.m. plane ticket for El Salvador, where Quintanilla has immediate family, the affidavit adds.
Quintanilla denied ever being in Steffey's home, according to his arrest affidavit.