Youngstown Police are investigating claims that the woman at the center of a murder investigation contacted a witness after she reached a plea agreement with prosecutors. 

According to police, a man flagged down officers on Friday, stating that he had been contacted by 35-year-old Katrina Layton. 

The man reportedly told police that he did not know Layton, but that he was a witness in the aggravated murder trial against Arturo Novoa, a case in which Layton was also previously charged with aggravated murder. 

According to a police report, the man stated that he had been told by Youngstown Police Detectives that Layton was not permitted to have contact with anyone involved in the case. However, he alleged that Layton sent him a thumbs up sign on Facebook, which he "believes means that she got away with the murder of Shannon Graves". 

Layton was released from the Mahoning County Jail late last month after pleading guilty to charges of obstructing justice and abuse of a corpse. 

Layton was originally charged aggravated murder, murder, and tampering with evidence as well. She's agreed to testify against Novoa, has given a statement about Novoa's alleged role in the case. 

Layton and Novoa were originally charged after the body of 28-year-old Shannon Graves was found in the basement freezer of a home in Campbell.

Members of Graves' family reported her as missing in June.

Novoa and Layton were arrested in July on charges of abuse of a corpse after a Campbell couple discovered Graves' frozen remains wrapped in trash bags.

According to a police report, detectives have been assigned to review the allegations of "witness intimidation". 

A court docket entry from Layton's plea orders that she is not to have contact with Novoa. However, documents available online do not specifically say she cannot contact others in the case. 21 News has reached out to the Mahoning County Prosecutor's Office for more information on the specifics of Layton's release/ 

No new charges have been filed against Layton.