Who murdered 11-year-old Maria Gonzalez in her Pasadena apartment?

PASADENA, Texas (KTRK) - Police are searching for the person who killed an 11-year-old girl. She was found strangled and sexually assaulted in her apartment while her dad was at work.

Families and police are trying to figure out who killed 11-year-old Maria Gonzalez.

The Pasadena Police Department responded just after 3 p.m. Saturday to an apartment complex at off Main Street near West Harris Avenue in Pasadena.

Maria's dad, Carmelo Gonzalez, said she texted him after he left work Saturday morning saying that someone was knocking on the door.

Family members went to check on her but they didn't see or hear anything. Gonzalez finished his shift at work and got home five hours after that initial text. He said he found her dead hidden under a bed.

"At this point, the father's alibi checks out, so he is, at this point, not considered a suspect in this investigation," Pasadena Police Chief Josh Bruegger said.

Police told federal investigators are helping to figure out what happened to Maria. DNA samples have been taken from people who live in the complex., but police said they're running into some roadblocks.

"Getting cooperation has been frankly, somewhat of a challenge," Bruegger said.

Gonzalez said Maria's mom was in Guatemala when the murder took place. He said he doesn't understand how someone could something this awful. He said he's not going to rest until he figures out exactly what happened.

There were security cameras in the area, but police said it is unclear if they were working at the time.

Police said there was no forced entry into the home. They don't have any suspects at this time.