Coincidentally, I'm in Pierce County too! I'm a licensed attorney in WA, working here under a pseudonym.
I apologize for the delay in getting back to you, but I didn't work here yesterday (Friday).
I am going to ask the moderator to take your names back off your question - we like keeping these messages anonymous.
But I'm awfully glad that you're in WA, since I'm most familiar with WA law.
First off, contact the bank. They should be able to help cut off that family member immediately.
If you want to pursue legal action, there are at least two things that you can do.
One is to file a complaint with Adult Protection Services, at http://www.adsa.dshs.wa.gov/APS/reportabuse.htm
Let them know that your Dad has been the victim of financial abuse/downright theft. APS will take this matter seriously. They will seek restitution from the thief.
Another option is for your Dad to sue the person in Small Claims Court. http://www.courts.wa.gov/newsinfo/resources/?fa=newsinfo_jury.scc&altMenu=smal
If you go the SCC route, be sure to also ask for reimbursement of the cost of filing in court, the cost of service, and interest.
Now, if your Dad is still cogent, make sure that he has given someone trustworthy Power of Attorney (for financial and medical), a living will (directions to doctors regarding end of life decisions, such as whether to connect to machines or not), and a will or living trust.
No, I can't represent anyone or take clients outside of Just Answer (in case you were going to ask). I'm pretty much retired (still licensed), but I have no clients and don't want anyone.
Again, my apologies for the delay in getting back to you.
Don't hesitate to keep writing.
My very best to you and your Dad,
PS I hope that your Dad is taking full advantage of what the VA has to offer. I hear from retired, disabled VA friends that services at American Lake and Madigan have really, really improved. There may even be some new benefits available. It doesn't hurt to ask!