Captain Alonzo Vandermeer was a male Human Starfleet officer who lived during the late 24th century. At one point in his career, he served as first officer under Captain Marta Batanides. By 2390, Vandermeer was the captain of the USS ibn Majid, a heavy cruiser, with Cristóbal Rios as his first officer. (PIC: "The End is the Beginning", "Broken Pieces").
In that year, while patrolling the Vayt sector, the ibn Majid encountered a small ship of unknown origin, and beamed aboard its two passengers, Beautiful Flower and Jana. Vandermeer received a "black flag directive" from Starfleet Security, which ordered him to kill the two beings, otherwise Starfleet would destroy the ibn Majid with all hands. Vandermeer murdered both of them with his phaser, and when Rios confronted him, he killed himself. (PIC: "Broken Pieces")