[Servant of the 9]

Second Chance' top of the line body armor a couple of years ago started using a new fabric that was stronger than Kevlar.
The material was known to deteriorate after 4 or 5 years and was to be replaced regularly. In use it was found that it deteriorated after less than a year. One police Dept, Baltimore I think, had a number of penetrations. They were suposedly all recalled.

This may have something to do with that.

So9

[Terabitten]

Second Chance' top of the line body armor a couple of years ago started using a new fabric that was stronger than Kevlar. The material was known to deteriorate after 4 or 5 years and was to be replaced regularly. In use it was found that it deteriorated after less than a year. One police Dept, Baltimore I think, had a number of penetrations. They were suposedly all recalled.

You're close. My job involves body armor for a large federal agency. The new fabric is called Zylon. The problem isn't that it deteriorates after four or five years - all fabric body armor does that. The problem was that it was suspected that Zylon deteriorated at an unpredictable rate. One Zylon vest might be a year old and totally unusable, another might be five years old and perfectly fine. There was no way to tell.

There is some argument that Second Chance may have used a bad manufacture technique, and that is what caused some Zylon vests to fail while others passed the NIJ standard. The bad construction technique would explain what appeared to be unpredictable deterioration, IMHO. If the vest was shot at one spot, it would work. If the vest was shot in another spot (which may only be a millimeter away from the first shot placement), the vest may fail.