He didn't, he left it at a gas station so it's finder would use it and lead the investigators astray. It's later in the article.
The author seems to think this was a good ruse, but I think I disagree; if I were an investigator, I think any coincidence, such as a cell phone accidentally left at a gas station, would be something I'd want to look into.
That may be, but it seemed to be the charges to the corp. credit card that really made them suspicious. The cellphone seemed to just be a quick confirmation that he was still alive. Though it would seem awfully suspicious for him to abandon his cellphone without reporting it missing/stolen (even if the police tracked down the thief).
[ I'm assuming he didn't report it missing, because the article doesn't say so, and because it doesn't make sense that messages sent to unknown numbers from a stolen cellphone would mean that he's alive to investigators. ]
The author seems to think this was a good ruse, but I think I disagree; if I were an investigator, I think any coincidence, such as a cell phone accidentally left at a gas station, would be something I'd want to look into.