HOUSTON -

Houston police have released the cause of death for the two women who were found dead after investigators responded to a standoff in Montrose.

Houston police said officers and a SWAT team responded to a second floor residence of Emerson Court apartments in the 200 block of Emerson at Garrott just before 1 p.m. Tuesday for the report of a murder/suicide.

Police arrived and found one woman, later identified as 67-year-old Terry Sullivan, dead inside the apartment. Officials said she died from a gunshot wound.

While checking for other victims, police found a second woman, later identified as 60-year-old Barbara Mayes, armed with a gun in the bedroom. Officers said they gave her verbal commands, but she was unresponsive.

The SWAT team responded to the scene and secured the apartment.

Investigators determined that Mayes was died from a self-inflicted gunshot wound.

"At this point, homicide is conducting their investigation.  Right now they are canvassing the area.  They are trying to make contact with any witnesses that may have been here, may have heard anything or may have known the two females that are there in the apartment right now," said Victor Senties with HPD.

Neighbors didn't know what was happening when police surrounded their otherwise quiet Montrose neighborhood.

"Obviously very surprising, especially around here.  It's usually pretty calm.  So it's not something you typically hear from this area," one neighbor told Local 2.

Autopsies by the Harris County Insititue of Forensic Sciences determined the cause of death to be a murder-suicide.