But when they examined the device, labelled “Homicide at Midtown Marriott" they found it contained 39 graphic images and 12 videos of a woman being strangled in a hotel room and pictures of her face down in the back of a truck, according to a charging document.
A man’s voice can be heard in one of them saying: “Just ... die.”
There are also reportedly pictures of the woman under a blanket on a hotel luggage cart near a truck and in the truck bed.
Investigators believe human remains discovered earlier this month are those of the woman seen in the videos.
As they they are work to identify the corpse and how she died, investigators arrested Brian Steven Smith on suspicion of murder.
During a brief court appearance earlier this week, the 48-year-old was not asked to enter a plea. A judge said he would appoint a public defender for Mr Smith, who said he could not afford a lawyer.
Deputy district attorney Brittany Dunlop said the process calls for the case to be brought before a grand jury.
Detectives believe Mr Smith recorded the events himself in early September, said Anchorage Police Department spokesman MJ Thim.
The South African national lives in Anchorage, he added.
Police reviewing the footage remembered Mr Smith, who has an accent, from another investigation.
They discovered he was registered in early September to a room at TownePlace Suites by Marriott in Midtown, Anchorage, where the carpet matched that in the footage, according to Anchorage Daily News.
They also used vehicle and mobile phone records in their investigation.
Associated Press contributed to this report.