Theft and fraud top the list of financial abuses for those over 65 years of age. Financial abuse can happen even though the senior is comparatively competent and living in their own home. Con men don't exist because people are stupid. They exist because they are very good at fooling people.
The classic example is the doting very elderly man with the sweet young thing who's after his money. She is not defined as an abuser. He doesn't feel abused - maybe. But the children certainly are quick to point out that their own - oops! - their father's financial interests are being abused. We have laughed at this old joke for decades. It’s funny as long as it isn't real. Maybe with the advent of 'cougars' the joke will have to switch genders!
On a day-to-day basis in real life, it's the bullying or manipulating grandchild who talks the elder into giving them money or family treasures for some fabricated reason. Or, it could be the "I really don't want to look for a job any more" adult child who moves in and lives off Mom or Dad on a pension. Potentially, it could be a flim-flam house repair artist at the front door.
Whatever the circumstance that leads the senior to lose monetary viability, it should be investigated and rectified as soon as and as much as possible. Seniors are no longer in a position to re-make the money they have spent a life time accumulating.