The original Plano scandal was the suicides in the 80's, then the heroin OD's in the 90's and then the steroid deaths/scandals in HS sports of the early 00's. The reason why all three were such big national news is because Plano was not the type of place parents expected this stuff to happen. It goes against the idea that cities with high instances of home ownership and decent schools are a safe haven against the big bad world.
Parents had this idea that their children being off the "mean streets" of Dallas made them immune to big city problems. Like manicured lawns and home owners associations somehow blocked bad things from happening.
The city has 275K residents and is surrounded by suburban sprawl on all sides. A few pockets of the city have taken a dive- mainly the older parts where homes are smaller and the city has a re-gentrification effort in place. Most of the city is subdivisions that were built in the 70's, 80's and 90's and the homes seem to get larger with each decade.
West Plano has some very posh neighborhoods that are in the top zip codes in the country (Willow Bend and Old Shepard Place) and just past the East side of Plano (but still in the school district) is Murphy- a city of 17K that is 100% single family homes and the average house is over 2500 sq. ft. Other than that, Plano is very normal. Some nice neighborhoods, some that could use a little work.
Living in the area, I can tell you that people in the area are talking about this case. The consensus is that it is tragic, the public is not in danger and like all good suburbanites, everyone says that drugs must be involved- I think people just want to think this could never happen to them because their little darlings would never stray from the life path the parents have planned for them.