Angelina County authorities are on the hunt for a man believed to have stabbed his girlfriend and her brother to death in an incident on John Kolb Road early this morning.  Capt. Allen Hill said the suspect is Terrance Demound Barnes, 31, who was living at the house but is from Center.  According to authorities, Barnes stabbed his girlfriend during a disturbance around 1:30 a.m. The woman's sister ran into the room and tried to pull Barnes off of the girlfriend, who was holding an infant. The girlfriend's brother then came into the room and got in a fight with Barnes and was stabbed.  The girlfriend, who was already seriously injured, ran out of the house and Barnes caught up to her in the driveway and cut her throat.  Both victims were reported dead at the scene. The victims' identities will not be released at this time.  Barnes is a 1999 graduate of Center High School.  If you have any information or know the whereabouts of Terrance Demound Barnes, please contact local authorities.