A search warrant is written to find a video taken by a defendant on his iPhone of him committing an offense. While looking through the phone for the video, the officer finds another video he took of him committing another offense. Should we get another search warrant for the unexpected video?

If the original warrant was an 18.02(10) warrant, and you want to get a second warrant based on what was discovered during the execution of the first warrant, that seems okay as long as you have it issued by one of the judges authorized by 18.01(d), since it's a subsequent warrant for 18.02(10) evidence. You'll want to make sure your office explains in the subsequent affidavit why they didn't know about the second video when the first warrant was issued and why they couldn't seize the second video via the first search warrant.

However, depending on the characterization of that first warrant to get that original video, you may have a "plain view" argument for the second video as well. Take a look at this case and the cases it cites to figure out if that's an option for you here. Carmen v. State, 358 S.W.3d 285, (Tex. App. Houston [1st Dist.] 2011)