General:
* Seize
* Grab
* Take
* Secure
* Obtain
* Acquire
* Gain
* Arrest
* Trap
* Catch
More specific:
* Record (for images or sounds)
* Conquer (for taking control of a place)
* Snatch (for taking something quickly)
* Imprison (for taking someone into custody)
* Entrap (for catching someone in a trap)
* Engulf (for surrounding and taking over)
* Hold (for keeping something)
* Retain (for keeping something)
The best synonym for "capture" depends on the specific situation.