Select Unique on 1 Column in Google Sheets - Distinct Doesn't

I'm trying to set up a kind of a bid thing, where the top 5 respondents receive a prize. I was hoping to use SQL to get the top 5, but I can't remove duplicate bidders and only take their top bid. I wanted to do something like this:

=QUERY(range, "SELECT timestamp, bid, DISTINCT name, department ORDER BY bid DESC LIMIT 5")

But DISTINCT doesn't work in Google Sheets. Any idea as to what I should do in this situation?

Here is my dummy data set (ignore the timestamps):

This is my desired outcome:

This is what I have so far. You can see that Jim and Susan are in the table twice and that Bob and Samantha have missed out on placing as a result of this.Using the query:

=QUERY(A3:D12, "SELECT A, B, C, D ORDER BY B DESC LIMIT 5")