WASHINGTON (AP) – Law enforcement officials say a note found in the car of a man charged in a Tennessee church shooting referenced retaliation for a white supremacist’s massacre at a black church two years ago in Charleston, South Carolina.

Investigators are not saying what motivated Emanuel Kidega Samson to shoot churchgoers Sunday. But the note could offer a glimpse into his mindset. The Associated Press has not viewed the note, but it was summarized in an investigative report circulating among law enforcement.

Two law enforcement officials read portions of the report to AP on condition of anonymity because they were not allowed to publicly discuss an ongoing investigation.

Samson is charged with murder for killing a woman and wounding six others. Federal authorities have opened a civil rights investigation.Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.