Orlando Gunman Omar Mateen Bought $9,000 Worth of Jewelry Days Before Shooting

The store owners say they are cooperating with investigators.

The purchase was made June 6 at the Kay Jewelers in Jensen Beach, Florida, which is near the Lotus Gun Shop where Mateen attempted to buy body armor.

Signet, which owns Kay Jewelers, would not confirm the purchase by Mateen, but issued a statement that they are "working closely with the authorities."

Investigators are still trying to piece together possible motives for the deadliest mass shooting in U.S. history.