The death of Susan Morrissey Ledyard, a teacher whose body was found in the Brandywine River in Wilmington in July, has been ruled a homicide, Delaware state police said Thursday.

The state Division of Forensic Science established that Ledyard, 50, a longtime teacher at Academy Park High School in Sharon Hill, died of blunt-force trauma and drowning, police said in a statement.

Ledyard’s body was found just before 7:40 a.m. on July 23 in a stretch of the river that flows through Wilmington, not far from where she lived, police said. The body had visible injuries and investigators said they had ruled out the possibility she killed herself.

On the morning Ledyard died, investigators said, she stayed up late, texting friends until 2:45 a.m. At 3:02 a.m., dressed in a purple tank top, she got into her black Honda Civic and drove two minutes to a road near a bridge. She then turned the headlights off and got out. Police said they do not know what Ledyard did between then and 7 a.m., when her body was spotted three miles downriver from the bridge.

The state police Homicide Unit is continuing to investigate and asks anyone with information to call 302-365-8441.