BROKEN ARROW, Okla. – Police arrested a man and his fiancée, charging them with murdering his ex-wife, who he was in bitter custody battle with.

Police arrested Richard Spaulding, 43, and Sonia Weidenfelder, 34, on Monday.

In November, a family member discovered the body of Debra Morgan, Spaulding’s ex-wife. Investigators said Morgan died from ‘unusual trauma.’

They also said Morgan and Spaulding had been fighting each other for custody of their child. Police said the custody battle may have played a role in the murder.

Fox 23 News in Tulsa obtained court documents showing Morgan won custody of their child.

The news station also received a letter that Morgan apparently wrote, detailing an abusive relationship she had with Spaulding, claiming he abused her “physically, mentally and emotionally.”

The child is in state custody.