Ensign Lynch was among those assimilated by the Borg when they attempted to take over the ship. Captain Picard shot him with a holographic tommy gun in the Dixon Hill holodeck program (with the safety protocols turned off) to obtain the Lynch-drone's neuroprocessor. The drone still had the remains of a Starfleet uniform and combadge underneath its exo-plating, which disturbed Lily Sloane.
Lily later cited Lynch's fate to Picard as an example of how he was letting his personal vendetta against the Borg get the better of him at the expense of his crew, but the captain insisted there was nothing that could have been done to save Lynch. (Star Trek: First Contact)