A prosecutor says an Oregon woman on trial for the murder of her 4-year-old son believed the boy was gay and that was a motive behind the deadly beatings.

Jessica Dutro's son Zachary died in August 2012 after collapsing at the homeless shelter where his family was living southwest of Portland.

The Oregonian reports a Washington County judge ruled Wednesday that a Facebook message from Dutro to her boyfriend was admissible evidence.

Prosecutor Megan Johnson argued the message established Dutro's motive for inflicting on Zachary a pattern of abuse.

In the message, Dutro told her boyfriend that Zachary was going to be gay, using a slur.

Earlier this month, Dutro's boyfriend pleaded guilty to manslaughter and assault for his role in the homicide.