She had found the beetle in a parking lot - no water nearby - which isn't too surprising. These beetles, water-loving as they may be, fly well and are often attracted to well lit places at night.
Even though this species and others of its ilk are termed scavenger beetles, many are predatory.
One feature that is apparent with the beetle in hand is the incredibly waxy smoothness of the carapace, or upper shell. It's like a freshly waxed surfboard, and such slickness undoubtedly greatly reduces drag while swimming.
Watch for these interesting beetles if you are around the margins of ponds, vernal pools or nearly any shallow vegetated wetland.