US believes Russia fabricates "evidence" of Ukrainian Armed Forces' "involvement" in killing the POWs in Olenivka - Associated Press

The Associated Press has written about this. 

The US intelligence officials have determined that Russia is seeking to plant false evidence to show that Ukrainian forces were responsible for the July 29 attack on Olenivka prison that killed 53 people and wounded dozens of others. A US official familiar with the intelligence report told the publication.

The official, who was not authorized to comment publicly and spoke on condition of anonymity, said that intelligence suggests Russian officials may be planting remnants of ammunition from HIMARS missile and artillery systems as evidence that the systems allegedly provided to Ukraine by the US were used to attack.