Police are investigating how a 12-year-old California girl disappeared and why her father received messages threatening her life, KCRA-TV reports.

Authorities on Friday found Lydia Ramirez shortly after her dad pleaded for her safe return.

The discovery came after Ramirez was seen on Thursday jumping a fence and getting into an unknown vehicle outside her school in Elverta, California, according to the Sacramento Bee.

The girl’s dad, Tre Watts, posted a video on Friday to Facebook begging for help finding his daughter. Compounding her disappearance were several messages discovered on the girl’s Instagram account.

“A bunch of her friends that know her at the school began to hit up her Instagram account that we had no clue that she had,” Watts said in the video. “We received back messages that were not sounding as if they were coming from Lydia, but coming from someone else.”

Watts said the first message read, “Don’t worry about her. She’s in the back of the truck and she’s not coming home.”

Another message indicated that she was being held by sex traffickers; it read: “Don’t worry about her; we’re in Reno now and she just finished her first job.”

The threats warned the girl’s family and friends to stop attempting to contact her.

“If we were a loved one or a friend, and we cared about her, we would stop messaging or you won’t see her alive again,” the message reportedly read.

Ramirez was later found in a north Sacramento apartment on Friday evening, according to the Sacramento County Sheriff’s Department.

“Detectives are still investigating but have determined she was not kidnapped, and at this time they do not believe sex trafficking was a factor in her disappearance,” the sheriff’s department said in a statement.

To report information about Ramirez’s disappearance, call police at 916-874-5115.

[Feature Photo: Lydia Ramirez/Family Handout]