SAN ANTONIO -- San Antonio police on Tuesday were investigating the death of a woman whose body was found in a Northside apartment.

The body of 49-year-old Cassandra Watkins was discovered at the Spanish Trace Apartments in the 7200 block of Blanco Road Monday afternoon, police said.

A relative asked the apartment manager to open Watkins' apartment after she didn't answer her phone, police said.

Police said the manager found Watkins facedown on her bed, covered in a blanket. An autopsy is being done to determine the cause of death.

Medical examiners listed Watkins’ cause of death as "homicidal violence."

San Antonio police Officer Matthew Porter said investigators found signs of foul play.

"Homicide did make the scene, collected evidence, and now they have opened a murder investigation," Porter said.

Porter would not elaborate on the extent or nature of her injuries.

Police are looking for a man who was reportedly the last person seen with Watkins, described as 5 feet, 5 inches tall and weighing about 180 pounds.

If you have any information about this killing, you are asked to call Crimestoppers at 224-STOP.