The NYT carries a story about how a man’s Metrocard history acts as a “silent witness” but this evidence is only misleading and capable of being planned. A Metrocard is not like the electronic bracelets that sex offenders wear; there is no proof showing the card was always with its owner.

While the Metrocard history backs up the murder suspect’s alibi, we don’t know if he was the one carrying the card all along. It does, however, help narrow down investigation of CCTVs. Given the timeframe of the murder and the exact timestamp of the Metrocard, authorities should check CCTVs to see if he was really at 205th street when he said he was. Of course, we know that subway stations have surveillance cameras. But during the past few weeks, if they were checking up on the suspect’s alibi, investigators should already been scouring through videos, right? It seems weird that there is no mention of surveillance camera activity on the turntiles. Maybe there wasn’t one- which would be weird because shouldn’t there be a camera looking at the turntiles?

[Timeline]

Cashed check at 11:39 p.m. – Confirmed by CCTV shot
Murder: call to 911 was made at 12:21 a.m. (Ogden Avenue and West 165th)
Boards at 205th St. (12:30 a.m.)
Boards 182nd Street (2a.m.)

Using the Metrocard as a locator is wrong in the same sense that using one’s Dopplr history to identify one’s whereabouts is wrong. Both can be manipulated in the case of a carefully planned murder.