SAN ANTONIO -- Police have launched a murder investigation after a passerby found a woman lying in a pool of blood near a San Antonio intersection, reports CBS affiliate KENS.

The gruesome discovery was made around  2 a.m. Wednesday, the station reports. The woman was dead when emergency responders arrived.

Police tell the station the woman sustained massive trauma to her head and face. Authorities say she may have been beaten or shot to death, but a medical examiner will determine her cause of death. Police believe she was not hit by a car, KENS reports.

Before the woman’s body was found, police reportedly received a 911 call about a suspicious person in the area. They’re not sure whether the report could be connected to the murder investigation.

The victim is described as a Hispanic woman about 25 years old. She has not yet been identified.