Breaking news, the two they had were basically in the wrong place at the wrong time.
They got a phone tip about the note the sniper left at the last scene, that they are deeming authentic, so they staked out the area. Lo and behold, a white Astro van showed up with 2 men in it, and they took them and the van into custody. Unfortunately, there was no evidence to link them, and it seems the worst thing these two have done may be immigration violations.
I hope they get this madman soon. It will be interesting to find out about him/them when they do. Personally, though, I don't think they will ever talk to him. I think he will either commit suicide as they close in, or "suicide by cop" making a situation where the police are forced to kill him.