I see this being used adjectivally, as in "he is an escaped prisoner," but I don't think I've ever come across "they are escaped" as a participle, only "they have escaped" - sounds archaic to me.

...King James Bible, acts 28:1: "And when they were escaped, then they knew that the island was called Melita" rendered "And when they had escaped, then they knew that the isle was called Melita" in Webster's Bible. Not sure what to think.