Last year, the facial recognition system picked out more than 1,000 cases that resulted in State Police investigations, officials say. And some of those people are guilty of nothing more than looking like someone else. Not all go through the long process that Gass says he endured, but each must visit the Registry with proof of their identity. “We send out 1,500 suspension letters every day,’’ said Registrar Rachel Kaprielian, who says the system has been a powerful weapon to fight identity fraud since it was installed in 2006 but that it is not without problems. “There are mistakes that can be made.’’ Neither the Registry nor State Police keep tabs on the number of people wrongly tagged by the system. But Gass estimates in his lawsuit that hundreds might have received revocation notices in error since the system was installed.