Well: it's also that James is @ 10 years older than Denise (similar in Short parents)
Both have one child: a girl
Denise worked at a plant (so did Mary Short, though if recall, a couple years prior to murder)
Both happened on the 15th
Jennifer Short found in October
Both parents shot dead, both middle of night (not many, or if any other apparent abductions, wherein one child taken under -at this point- unknown circumstances - wherein both parents shot dead, there are other violent abductions: but not precisely like this aside from Short family that I know of)
I think, if there is a connection, that the perp is either a truck driver and/or has worked & now does work at a processing/factory plant (could be a truck driver for a plant)
I could go on

But I shall spare you all that.....JMO