I agree with you that they should immediately have taken him in because they knew he was illegal. What chaps my hide is that in 2014 when he beat up his wife, ICE but a hold on him, and he was out on bond before the day was over. That deportation case, after two years, still had not come up yet. Scary to think that he was released that afternoon to possibly go back and injured or kill the wife (in 2014).
My hunch is that they may have known that Kayla was dead on Tuesday night. Believe they interviewed them then and and with those scratches I would think they would have known. Perhaps they were acting as they believed him to find where her body was. So many missing persons are never recovered in East Texas due to the brush and remote areas. I did a Google street view of where he lived and no near neighbors.
When this goes to court, I bet there will be lots of information that we didn't hear about. I also bet there are other victims of this creep. From his FB before marrying Kayla's cousin, looks like he might have farmed. Some pictures are maybe Colorado. If he was a migrant worker, he could have drifted and victims could be hard to find, but if the truth comes out...I bet they are out there.
The biggest screw-up, in my opinion, was dragging his deportation out for over 2 years.