It is a recognised phenomenon and yes, it is predominately men who kill their children (and sometimes their partners/ex partners) then themselves, or at least attempt to.
Thing is, every time a case like this comes up, on the interwebs, in the newspaper opinion pages, over the water cooler and at the school gates, discussions emerge which seem to take a tone as if nothing like this has ever happened before (even if it did just last month, when they were last talking about a similar case.)
If you do a search for the work of Professor Jack Levin, you'll follow a trail of extensive evidence on the subject of "Family Annihilators," building up a pretty accurate picture of the factors that precede many of these murders.
This article from the Quarterly journal of the Domestic Violence Resource Centre in Australia explains some of the common features of these cases. I'd encourage folks to have a full read of the article. Here are some brief key points from it.
Common perceptions are that he must be mentally ill and/or have an extensive history of physical violence against the children. The community would like to believe that these men are unique, that the problem lies within a few pathological individuals. It is certainly easier to believe that than to admit we may be living in a society which still allows men to see women and children as their (disposable) property . . .
^In the absence of any diagnosis with which to explain the horrific actions, these deaths are almost always portrayed ? particularly
by those defending the killer ? as spontaneous, tragic moments of distress.
The father is alleged to have been suddenly pushed over the brink with despair, and to have acted impulsively. However research shows that this is not the case at all.^
^Akin to a provocation defence, these fathers usually argue that they were driven to their crimes by their partner?s behaviour. . . News headlines sensationalise the killers? excuses, such as: ??sordid affair and the husband driven to murder?; ?Sex obsession of mother blamed for murder of innocent
child? . . . Explanations offered by relatives and friends of the men often suggest the woman caused her children?s deaths . . . ^
I find the reporting of these cases in the media to be fascinating and disturbing. They seem to follow a formula, a script designed to justify the act in some way and portray the mother (even if she is also killed) as culpable for the father's action.
The article I've linked to also cites research showing that when mothers kill, the media and collective social response is very different. They are mostly seen as evil, or at best as mentally very sick and deranged. However, when fathers kill, the media bend over backwards and sideways to portray them as just ordinary guys, even loving, caring, devoted husbands and fathers.