Part of the crime scene where Pastillas Girl Angelica Yap's mother, Teresa, was shot dead in Caloocan City, Sunday night. ABS-CBN News

MANILA (1st UPDATE) - The mother of Angelica Yap, also known as "Pastillas Girl," was shot dead by an unknown gunman in Caloocan City, Sunday night.

Teresa Yap, also known as "Teteng," sustained a gunshot wound in the back of the head.

A closed-circuit television (CCTV) camera of Barangay 131 caught the whole incident.

Yap was with one of her daughters and her niece and was about to eat at a roadside eatery in Tagaytay Street in Caloocan when a man suddenly approached her from behind, shooting her at close range.

Yap fell as the gunman fled the scene. Her family and other concerned citizens in the area immediately responded.

She was brought to a hospital but was pronounced dead before midnight. Angelica went to the hospital after she learned about the incident.

According to a relative, Tumping Fabian, Teresa received a lot of death threats via text messages saying she would be finished before Christmas.

The messages made her worry but Teresa allegedly ignored the threats.

Police officials and investigators were still gathering information about the incident as of posting. Residents were helping the police and barangay officials in their probe.