24yo abandons car running in street, boards bus, and vanishes — but surveillance footage shows she was not in distress

Newly released surveillance footage shows 24-year-old Sydney Marquez appearing calm and without obvious signs of distress.

Marquez vanished near Houston’s Asiatown area on the night of December 11, 2025. The footage shows Marquez walking along a sidewalk in Houston’s Asiatown area. She then walks out of frame.

According to Houston news outlet KPRC, Marquez had been visiting friends in Houston when she was last seen. Reports say she left her friend’s car running and unattended in the middle of the street and walked away.

Marquez’s own car and belongings recovered

Marquez’s own car was later found abandoned near Houston’s Chinatown, with her belongings — including phones, clothing and makeup — left inside.

Some witnesses said she may have boarded a northbound METRO bus on Gessner toward Little York. Family members describe Marquez, a Texas A&M University graduate, as a bright and accomplished young woman.

Marquez’s mental health struggles

But her father, Raul Marquez, told reporters that doctors diagnosed his daughter about a year ago with late-onset bipolar disorder and schizophrenia. He said she had not been consistently taking her prescribed medication in the weeks leading up to her disappearance

“It’s been a nightmare ever since we found out my daughter was missing,” Raul told Houston’s KPIR. “The best Christmas gift in the world is just to bring my daughter back. That’s all I want for Christmas.” Her father particularly emphasized that leaving behind her phone was out of character and concerning, given that she regularly uses it.

Investigators from the Houston Police Department’s Missing Persons Unit continue to lead the case, along with Texas EquuSearch, a nonprofit search and rescue organization. The newly retrieved bus surveillance footage offers potentially crucial insight into Marquez’s final known movements.

Authorities have not released additional details about what the footage reveals beyond her presence on the bus. HPD describes the investigation as ongoing and has not publicly confirmed any potential sightings or significant new leads.

Friends, family and search volunteers have been actively canvassing the area where Marquez was last spotted, gathering and reviewing surveillance camera footage from nearby businesses and intersections in hopes of uncovering new clues. Despite these efforts, more than ten days after her disappearance, there has been no confirmed contact with Marquez.

Marquez is described as 5’3″ tall, approximately 110-120 lbs, with brown hair and brown eyes. On the night she vanished, authorities say she wore a black shirt and black pants. She might be carrying a pink bag.

Authorities urge anyone with information to contact the Houston Police Department’s Missing Persons Unit at (832) 394-1840 and reference case No. 1618418-25. Every piece of information, officials say, could be vital in piecing together what happened to Marquez.