ALL GOOD THINGS: don't come to the viewer who waits

ALL GOOD THINGS is a well acted but ultimately frustrating exploration of a real life case which spanned three decades and involved 2 murders and 1 mysterious disappearance.

The common link is David Marks (Ryan Gosling), the rebellious but weak oldest son of a wealthy New York family which owns a large amount of land in mid-town Manhattan. His youthful rebellion against his domineering father (Frank Langella) takes the form of an unsuitable marriage (in dad's eyes) to Katie (Kirsten Dunst) and a brief spell running a health food store in Vermont. But when dad threatens to cut off the funding the couple return to New York and David reluctantly takes his place in the family business.
David's always been a little strange but once he's back under his father's control he starts acting seriously weird and there are incidents of violence against Katie. Then one day in 1982 she disappears never to be seen again. ALL GOOD THINGS wants to make the case that David murdered her, but because this is a story based on actual events and the real life David (under a different name) is still alive, director Andrew Jarecki is forced to be more circumspect than he would probably have liked. So what we get is an apparently solvable mystery if only one of the characters would ask the right questions. The same is true of David's behaviour. Several possible causes are hinted at but never explored by either friends and family or the police.
What we're left with is a bunch of fine performances - Gosling's portrayal of David over 30+ years is excellent, and Langella is particularly repellent as the father with an accounting ledger for a heart - but a gnawing sense of dissatisfaction. I didn't expect all the loose ends to be tied up with a pretty bow at the end of an hour and forty minutes, but a few answers would have been nice.