I don't know when the house was built; however, there was a time in the early 70's when the electrical code allowed copper and aluminum to be used together in residential housing construction (the was a "boom" period, and this was intended to alleviate material shortages). The problem is that these metals expand at different rates under electrical load with the result that at switches and outlets the connections loosen (where you connect the wire with a screw. At first this loosening just increases the resistance, and the outlet and several feet of wire heat up a lot. Then you get some arcing at the connection. Of course, everything is nice and hot so then a fire starts easily and spreads quickly.
We bought one of these houses over in the Glenshannon tract off 59. The "fair warning" that came with house was that we really ought to go around and check every switch and outlet at least once per year and make sure they were tight. Even with that, we had a couple of minor fires in the kitchen at a particularly heavily used outlet (on serval other occasions I noticed that outlet and adjacent wall were hot and was able to forestall any problems by tightening the connection). Eventually, the developer came back and re-wired some of the houses (lots of people were oblivious to the problem) but not all of them.
The fire discussed here is consistent with this kind of problem; however, I don't see anything in the report about electric except that two CB's were tripped off (i.e., no direct attribution to wiring).
The house appears to be of that vintage.
I hope this was nothing more than a terrible accident. I can't believe anyone would truly want to murder my friend. I also don't understand why he didn't escape. He was no fool.
re: aluminum wiring. Yes, there was a period when aluminum wiring was used in the era that you mentioned. Many times, there were problems with the dissimilar metals causing loose connections unless the properly rated receptacles and breakers were used. Loose connections do heat up (I have seen it myself as evidenced by charred breakers and such) and can cause fires. But usually, there needs to be a fair amount of current flowing through the connection for it to heat up. More current = more heat. And this type of problem will not usually trip a breaker unless or until insulation is melted sufficiently to cause a short circuit. So this is a potential source of fire.
The question is; was there sufficient current flowing across a loose connection in the dining room to create enough heat to start a fire? And, if it did, would it be a type of fire that grew at a sufficient rate as to surprise someone that was presumably alert in the next room?