In Phoenix, an investigation is under way after a bullet passed right through a Kevlar bulletproof vest, seriously wounding an officer. An internal memo went out to officers last week, asking them to be aware of their bulletproof vests and the level of protection they offer.

It alerted them to the investigation, triggered by something they had never seen before. "It's critical. It literally does save lives," said Joe Clure with the Phoenix Law Enforcement Association. "We want all of our officers to wear a body armor, and we want them to have confidence in that vest."

That confidence is being questioned after an ex-con fired a 40 caliber round through a Phoenix police officer's bulletproof vest. "This is the first time in my recollection of almost 30 years that I recall a vest being penetrated," Clure said.

Officer Anthony Daley, 30, was shot at close range in the abdomen which was covered by a Kevlar ballistic vest, manufactured three years ago by Custom Armor Technologies which no longer is in business.

The hollow point bullet fired right through the lower edge of the vest and according to the National Institute of Justice, it may not qualify as a failure for the soft body armor. "When you look at the NIJ standards, it talks specifically about the 2 to 3 inch margin around the outer edge of the vest as potentially not having the same ballistic protection as the center mass area."

In the meantime of completing the investigation, officers are encouraged to wear their bulletproof vests. "These vests have proven themselves time and time again," Clure said. "Thousands of officers across the country have been saved by these vests."

Each Phoenix police officer is given an $800 stipend every five years to purchase the vest of their choice and comfort level.

The department is trying to figure out how to keep other officers safe, who may be using the same vest Officer Daley was wearing.