A man seen pushing a red or pink woman’s bicycle Sunday night at the University of Texas at Austin is the primary person of interest in the hunt for student Haruka Weiser’s killer.

Austin Police Chief Troy Gay showed surveillance footage during a Thursday news conference of the man, who sported a backpack and walked while pushing the bike instead of riding it. It's unclear who owned the bike.

Gay appealed to anyone near the north side of the football field around 11:30 p.m. Sunday to come forward if they had seen the man.

Weiser’s remains were discovered Tuesday morning, and police revealed a timeline of her disappearance on Thursday.

She was seen leaving the drama building on campus bound for her dorm between 9:30 and 9:45 p.m. on Sunday night. She had “communicated” with one of her friends and police said they believe they know the direction of her travel.

“She never made it to her dormitory that night,” Gay said.

Weiser’s roommates called university police the next day to report her missing and her body was found in a creek on campus Tuesday.

An autopsy concluded the death was a homicide and that she had been assaulted. Gay would not comment on the nature of the assault.

"The unthinkable brutality against Haruka is an attack on our entire family," university President Gregory Fenves wrote in a statement Thursday afternoon. "Law enforcement is fully engaged to do everything to bring the perpetrator who committed this crime to justice."

Weiser was a first-year Theatre and Dance student recruited to the college from Portland, Fenves said.

Fenves said Weiser was trained in ballet and was involved in a
student-run organization for dancers, Dance Action. She also performed at a fall concert.

"Haruka was a beloved member of our dance community, liked and admired by her classmates and respected by professors for her intelligence and spirit," Fenves wrote.

Extra officers and police vehicles were spotted on campus, according to The Daily Texan, and the university has increased the number of van shuttles for students. A program where volunteers walk with students, SURE Walk, has reported a 400 percent increase in users since the woman’s body was discovered.

“I have spoken with campus public safety leaders and am writing to assure you that we are doing everything possible to ensure safety on campus,” Fenves said in an earlier statement to students.

Tuesday’s discovery came just three days after police were called to the campus for a suspected burglary and sexual assault of a student, according to The Dallas Morning News. Police believe the student knew the suspect, who has not been named, in that case.

The Associated Press contributed to this report.