Special counsel Robert Mueller found no evidence that anyone connected with President Trump or his 2016 campaign conspired with Russia to subvert the election, according to a summary of his findings released Sunday by Attorney General William Barr.

Yet Mr. Mueller did find actions by Mr. Trump after he was in office that could be seen as efforts to obstruct the investigation into the election. Mr. Mueller did not recommend prosecution, but he left the decision up to Mr. Barr, who said he doesn’t see enough evidence of a crime to pursue charges.

“Deputy Attorney General Rod Rosenstein and I have concluded that the evidence developed during the special counsel’s investigation is not sufficient to establish that the president committed an obstruction of justice offense,” Mr. Barr wrote in a letter summarizing his findings. The letter was sent to Congress on Sunday afternoon and quickly became public.

Mr. Barr said one main factor in his decision was that there was no evidence Mr. Trump or his team conspired to work with Russia to subvert the election. That meant it would be tough to find corrupt intent behind the president’s actions even though they might, in another context, have been obstruction.