Their having it makes it certain that Flack and Lopez did it.
5 seconds sound clip from the The Big Trail (1930) movie soundboard.
You can hear this line at 01:47:41 in the Blu-ray version of the movie.
Quote context
[...]
- You overplayed your hand that time, Lopez!
- Zeke, this is old Ben Griswell's knife.
- Well, where'd you find it, boy?
- Lopez just left it sticking in my bedroll.
- Their having it makes it certain that Flack and Lopez did it.
- Killed my best friend. I been on their trail ever since.
- That's a serious charge. If you're sure, we'll call a settlers' meeting in the morning to try 'em.
- You can call a settlers' meeting to bury 'em.
[...]