The boyfriend of Dahj Asha, murdered in her Boston flat in 2399 by masked Romulan assassins whose attack triggers her dormant android abilities.
Caler appears in the opening scene of Remembrance, the first episode of Picard. Background sources identify him as a Xahean, the species introduced in Short Treks and Discovery.
He and Dahj are spending an evening at her flat in Greater Boston, celebrating her acceptance as a research fellow at the Daystrom Institute. Without warning a team of masked intruders beams into the room. One of them stabs Caler, who dies almost at once, and the others seize Dahj, put a hood over her head and begin to question her about where she comes from.
Something in Dahj activates. She kills all of her attackers in a few seconds and is left kneeling over Caler's body, with a vision of Jean-Luc Picard's face in her mind that sends her to France to find him.