Could be a PDA or cell phone. I have very old phone numbers. Also, the safe houses may still have been in use, with Shakir not knowing that their location was known by law enforcement. It's not clear by this story.
I hadn't thought of old digital remnants. I still think scraps of paper in the pocket. I'm old school.
But I don't think they had PDAs is 1993 and not many people keep the same cell phone for that long. A 1993 cell phone would be the size of kid's shoebox!
I suppose its all possible, but it still strikes me as unlikely. Maybe some old computer files survived a few computer upgrades and were lurking forgotten in some corner of his laptop.