A recent U.S. Supreme Court ruling requiring proof of kickbacks or bribes in prosecutions involving the theft of so-called honest services left prosecutors with “little choice” but to dismiss charges against two former Westar Energy executives, the U.S. Attorney’s Office said Monday.

“The law no longer supported our position,” U.S. Attorney Barry Grissom said in a statement. “We were duty-bound not to go forward with the prosecution.”