Dylan T. Hankewycz, 18, of no fixed address, faces charges of robbery, simple assault, theft, and receiving stolen property, according to Hanover police.
Hankewycz last week asked the 34-year-old victim several times if he could use his cell phone. When the victim denied his request, he pulled a pocketknife and demanded the phone, police said.
The victim later purchased a new phone and was downloading photographs from his carrier’s server when he found pictures of the man who robbed him, police said.
Police said Hankewycz was identified through his “self-portraits” and was arrested while he visited a relative.
He was sent to York County Prison on $100,000 bail and a probation detainer.