I've been thinking about this a lot. The blunders of this 'criminal mastermind.' And I think it's pretty simple;
BK was extremely well prepared for the coverup. Being a Criminology PhD candidate gives him insight into all of the investigative techniques. JMO
But BK couldn't account for the parts that contained variability. Which was the time and day the victims would be most vulnerable and how they would react inside of the house. MOO
I think BK drove around at night dressed in the dickies suit with a trunk containing everything he needed to commit a murder and cover it up. And for whatever reason (academic issues, thanksgiving break) he thought that night was appropriate. MOO
I don't believe for a second that he somehow thought his car wouldn't be caught on any cameras. I think he long accepted and reasoned with this in his planning. He likely knew where most of the cameras were. I think he just thought his generic white sedan (thanks for that) would provide him a buffer and his regular seemingly innocent drives through the neighborhood (this alibi might have been successful without the dna) would provide him reasoning if it ever got to that. MOO
Same goes for the cell phone. Those things on their own aren't much. IMO.
The
Locard's Exchange Principle most explains this approach and reasoning, IMO. He thought that as long as he took care to dress the part while inside (not leaving anything behind, OOPS!) and disposed of everything he took with him. LE would have nothing. JMO
One more thing I'll say that kind of supports my argument of BK methodically planning out this crime. And attempting to account for every possible variable...... "I'm here to help". Those words are from the PCA ...AND could have been an answer to any of the questions in the Reddit questionnaire he posted. JMO
MOO