I for one am not at all concerned about that (other than the general concern that I have for everyone everywhere, especially the vulnerable). I just don't follow any logical reasoning that would mean they are somehow in harm's way.
1 If SP killed their mom because she was in the wrong place at the wrong time, how would that somehow have them at risk of him wanting to find them and harm them? It just doesn't follow. In that scenario, MB has no connection to SP, and neither do her kids.
2 Or, if SP killed their mom because he had something against her and wanted her dead, again, how is that somehow going to carry over into some quest for harming/killing the kids she left behind? Once SP killed MB, he had done what he wanted, which was to make MB dead.
Since we have no idea what the motive is, let's assume that it was to silence MB. What if she knew something and SP needed to make sure that information was safe? Who else knew? Did her husband know? her daughters? What if MB's daughter (AB) was a partial witness to said information since she often accompanied MB to class? Without a known motive, there are legitimate reasons for those surrounding the deceased to be legitimately scared. If you don't think that entire families are ever killed off, look no further than Pike County. There were numerous crime scenes and numerous "nuclear" families killed.
I know that if my spouse had been brutally murdered, especially in situation where he was possibly ambushed, that I would not sleep well until the suspect was caught and jailed. I would keep wondering if the perp would show up when I slept, would be waiting for me whenever I came home or went to a new location, or if (s)he was watching my children. And if you listen to victims of crime talk about their experiences, they frequently say the same thing. They also express fear about convicted criminals being released even after several years have passed.
I don’t think video exists of the final confrontation. But IF it did exist I believe we would be able to glean significan clues such as height, size, strength,proportions, movements and mannerisms, dominant hand and probably figure out the gender, and possibly lead investigators to where DNA could have touched. So it would be big. But I think it is off camera and purposely out of camera range
The other huge thing about the confrontation being caught on tape is that we would likely not have to guess about whether this was a planned burglary or a planned murder. If the suspect is seen crouched in position and waiting for MB, it is likely to be a planned, premeditated murder. This would go to both motive and the charges itself. If, on the other hand, MB and SP bump into each other, that would likely support a spur of the moment killing. Did SP and MB interact before she was killed? What if MB was able to pull the helmet off SP? Would SP's identify have been revealed? Having video evidence of the crime itself would aid investigators as it would provide several clues and pieces of evidence.
I still don't think that CCoC was coincidence. MB would be alone, and even if she screamed, no one would be there to help her. She didn't stand a chance. I also think that the somewhat tight timeline points to this being a premeditated murder. According to police documents, it took between 10 and 12 minutes for everything to unfold. MB arrived at 4:18 and entered the church around 4:20; what is believed to be the suspect's vehicle was seen leaving around 4:30. If SP was still randomly roaming around the building, the chance encounter would have happened fairly shortly after MB arrived. Based on the wording of the initial SWs, it sounds like SP was lying in wait for MB. If SP knew what he was going to do, a simple hit to the head and few extra swings of the hammer would have completed the job. He could have then been on his way with time to spare.
Here's the other thing that nags at me about the chance encounter theory. If SP really was there just to B&E or steal AND he thought that he had all of the time in the world (since it was an early rainy Monday morning at a church), why was all of the damage to the church done in the back of the building? Rather than struggle with removing the lock, why didn't SP just enter under the awning? Those doors were solid glass, and we all know that SP has a propensity for breaking glass. Occam's Razor seems to indicate that would have been the easiest point of entry. Also, why park behind CCoC? If SP picked this location because he could burglar without threat of being caught, he would have no reason to worry about anyone stumbling upon his car or the broken glass until well after he was gone. However, we know that SP entered through the rear of the church, parked his car in a place where it could not be seen from the street, and only smashed glass in the north/east halls. Not coincidentally IMO, MB was killed in the SW quadrant of the church. JMO
ETA - And why would SP continue to carry a hammer through the church with him? If the hammer was used as a breaching tool, why not leave it by the door once he gained access to the church? As we see on the video, the interior doors were unlocked. He didn't need to the tool for access. It seems rather cumbersome to carry around a hammer.... unless SP knew that he would need that hammer at a later point in time.