A Texas man turned himself in to police after he used a screwdriver and hammer to kill three young siblings, including one baby of his own.

According to an arrest affidavit filed in Galveston County court, Junaid Hashim Mehmood, 27, is being held in the Galveston County Jail on three charges related to the attacks: capital murder of multiple people, capital murder of a child under 10 years old, and aggravated assault with a deadly weapon. Mehmood also confessed shooting his girlfriend in the face with an "aerosol pistol,” reported the Houston Chronicle.

Police were first called to an apartment complex on Jan. 3 when Mehmood's brother called police after he saw blood covering the walls and floor of his brother’s apartment. When police arrived on the scene, they found three deceased children and a trail of blood leading to the bathroom. Inside the bathroom, police found Mehmood's girlfriend, Kimaria Nelson, lying on the floor covered in blood.

Nelson was transported to a hospital in serious but stable condition.

The three deceased children were identified 16-week-old Ashanti Mehmood, 2-year-old Prince Larry Brown, and 5-year-old Angela Pilot. Ashanti was the suspect’s daughter and Nelson was the mother of all three children, the Associated Press reported.

Mehmood eventually was taken to the Texas City Police Department. Police said he waived his rights and confessed to shooting his girlfriend in the face with a pellet gun and killing the three children, the affidavit said.

Mehmood told police he stabbed Prince Larry Brown in the heart and chest multiple times with a screwdriver, according to the affidavit. He also said he struck Angela on the head with a hammer, stabbed her with a screwdriver and broke one of her arms. He told investigators he killed Ashanti but could not remember how, the affidavit states.

Police suspect a possible motive for the killing could be Mehmood was enraged after getting fired from his job. After the killing, Mehmood made a chilling post on Facebook that said, “I’m sorry.. I was a great man to everyone.. I do apologize ohh and thanks for firing me. Sorry to my family and my girlfriend family and most of all sorry to queen Kimaria Nelson.”