Police believe one or more suspects used the device in several incidents in Philadelphia, Bucks and Montgomery counties.
Detectives said in addition to reading ATM card numbers, the device included a small camera to record PIN numbers being entered by unsuspecting customers.
Captain Roland Lee of the Philadelphia Police Department's Major Crimes Unit explained that the skimming devices are relatively easy to assemble. A magnetic strip is installed and records the information off the card when it's inserted.
"It can fit right into the ATM, so to a person not expecting, it looks like it's part of the regular equipment," said Lee. "A person who has a little bit of electronic or mechanical skills could put it together."
Police feel confident these three caught on surveillance cameras had those skills to assemble and install the skimming devices.
It's an ongoing problem with 20 skimmers discovered in Philadelphia this year alone. The same such skimmers are popping up on ATM's in the suburbs. Police need the public to help identify these persons of interest and take steps to protect themselves.
"Every time I go to an ATM I do a quick sweep, make sure everything is legit," said Lee. "And then when I put my code in I make sure I cover it up first."
Surveillance pictures released by police on Thursday show one man described as a person of interest in the case.
Anyone who recognizes the man in the surveillance photos is asked to contact the Philadelphia Police Department's Major Crimes Unit at 215-686-3396/97, or dial 911.
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