A jewel thief has been identified by police by the cell phone he left behind at the scene of the crime.

Police said 27-year-old Germain Ibrahim Fofana and a woman entered a jewelry store in London with a child in a stroller, The Associate Press reports. Fofana and the woman were looking at engagement rings and then left. The suspect returned later, alone, and grabbed two diamond rings and a wedding band before bolting out of the store.

Fofana left his cell phone in the store, with a photo of himself as the screensaver.

Police said the thief is believed to be responsible for other jewel heists in the London area.