Brian Smith was charged with the murder of Kathleen Henry on Tuesday when a woman discovered a memory card allegedly laden with images and videos of the killing.

On September 30, an unidentified woman alerted Anchorage law enforcement to an SD card she found on the street. Blatantly titled “Homicide at midtown Marriott,” the card contained 39 pictures and 12 videos of a man strangling Kathleen Henry to death. In one portion of the footage, her killer can be heard telling her to “just … die.”

Two days later, authorities were alerted to the presence of unidentified human remains near milepost 108 on Seward Highway in southern Anchorage. According to a statement, Anchorage detectives believe the remains are Henry’s. Detectives found timestamps on some of the media, concluding that she was murdered during the first week of September.

During that window, suspect Brian Steven Smith was registered at Marriott’s TownePlace Suites. Smith was apprehended at the Ted Stevens Anchorage International Airport on Tuesday. The 48-year-old South African immigrant did not enter a plea during his arraignment on Wednesday and will likely be assigned a public defender for legal representation.

Authorities released a statement on Facebook thanking the unnamed citizen for her efforts: “The Anchorage Police Department extends its gratitude to the citizen who stepped forward with the evidence of this crime,” they said. “They played an instrumental role in making sure Smith will be held accountable for his actions. This serves as another example of when you see something suspicious, say something.”