capturer

To capture, in the literal sense of seizing or catching (capturer un animal, un fugitif) and, especially with digital tools, to capture an image or piece of data (capturer une image d'écran).

• Les gardes forestiers ont capturé l'ours qui rôdait près du village. — The rangers captured the bear that was prowling near the village.
• L'appareil capture automatiquement une photo toutes les cinq secondes. — The device automatically captures a photo every five seconds.
• La police a capturé le suspect après une longue traque. — Police captured the suspect after a long manhunt.

For screenshots and digital capture, capturer (une capture d'écran) is standard — don't confuse it with photographier, which implies deliberately taking a photo rather than grabbing existing on-screen content.