habían achacado
-they/you had attributed
Antecopretérito para el sujetoellos/ellas/ustedesdel verboachacar.

achacar

Buscaron a sus amigos, que habían achacado su desaparición al hecho de haber pedido prestado dinero y no tener con qué devolverlo.
His friends were looked up, and they put his disappearance down to the fact that he had borrowed some money and could not pay it back.
Palabra del día
el cementerio