Investigators are searching for clues into the death of a teenage girl in Northwest Harris County. On Thursday, the body of 18-year-old Trang Van was found in a bedroom closet on the 10100 block of Lazy Lagoon. Her father was the one who made the discovery.

"He came knocking on the door screaming. By the time I got downstairs, he was already gone. I came outside and saw him over here, and I yelled at him, what's wrong? He said someone killed my daughter, someone killed my daughter," said next-door neighbor, Gabriel Garza.

Garza called 911 for the distraught father and waited with him for help to arrive.

The teen's family told investigators Van was last heard from shortly before noon on Thursday. She was supposed to take a test around 2 o'clock, but she never made it.

Harris County Sheriff's Investigators canvassed the neighborhood asking neighbors if they noticed anything out of the ordinary.

"It was totally normal there where no cars parked outside. I couldn't tell that something unusual was going on," said neighbor, Grace Lee.

Investigators are not revealing how Van was killed. Her family told 39news there was no visible sign of a forced entry, but that the teen had been arguing with someone on her cell phone in the days leading up to her death.

Van's uncle says the family is in total shock.

"We don't know what is going on. We really don't know," said Chi Van, one of Trang Van's six uncles.

He said the aspiring teacher had recently graduated from Cypress-Fair High School with plans to attend the University of Houston in the Fall.