It’s been more than half a year since Elaine Park, a 20-year-old from La Crescenta who vanished in late January, disappeared.

On Tuesday, her mother came forward, once again with a plea.

“Losing a daughter is the hardest thing a mother can experience,” Susan Park said on Tuesday during a news conference, where friends, family and supporters offered a $250,000 reward for information that leads to her daughter’s whereabouts. “The uncertainty is the worst part. Not knowing what happened to her. You can’t imagine what it’s like going through so much pain that your heart is numb and … any mother should not have to experience this.” .

Private investigator Jayden Brant and others, including Michael Einziger of the band Incubus and writer Neil Strauss, both of Malibu, joined Susan Park on Tuesday.

“Based on information obtained during the investigation, we firmly believe Elaine did not commit suicide, and she is not a runaway,” Brant said, adding she is an involuntary missing person and he believes foul play was involved.

“We need more information,” Brandt said. The reward announced Tuesday is being offered until 11:59 p.m. Sept. 15.

“We were able to secure such a large amount, but unfortunately the stipulation on that from our donors is they want Elaine found now,” Brant said.

• PHOTOS — $250,000 reward offered to find Elaine Park of La Crescenta, missing since January

• VIDEO — Public’s help sought to find Elaine Park, 20; her car was found in Malibu

Elaine Park was last seen at 6:05 a.m. Jan. 28 when she left the home of her ex-boyfriend in Calabasas..

During a February news conference, the Glendale Police Department said they weren’t looking at Park’s on-and-off-again boyfriend because he had been cooperative.

Sgt. Robert William, a Police Department spokesman, said Tuesday that police received “speculations, suspicions and theories” about the disappearance from the private investigator, and it has all “fizzled out.”

There’s no evidence of a crime and the case remains unsolved, but police are continuing to investigate until she is found, William explained.

“We understand the mom’s position,” explained William, adding police have been asked to dig up a backyard but they can’t without a search warrant. “Her only child has gone missing.”

Elaine Park’s charcoal gray 2015 Honda Civic was found on Feb. 2 on Pacific Coast Highway just south of Corral Canyon Road in Malibu. The doors were unlocked, the keys were in the ignition and her phone, computer, backpack and cash were inside the car.

Before her disappearance, Park had attended Cal State Northridge and was headed to Pierce College, family members said.

She had small roles in television shows, including “Desperate Housewives,” “E.R.” and “MAD TV” and performed in several dance companies and musical theater, her family said.

• RELATED STORY: Glendale police suspend search for missing 20-year-old woman, but investigation continues

• RELATED STORY: Mother of Elaine Park seeks answers weeks after daughter went missing

Earlier this year, family members offered a $5,000 reward for information leading to finding Park.

A Facebook page titled “Help Find Elaine Park” was also created about six months ago. Creator Rosemarie Wheeler said on Tuesday the 20-year-old “has a smile that lights up a room,” and she wanted to help out Susan Park.

“What do you say other than how can I help or what can I do?” said Wheeler, who added her daughter went to school with Elaine Park. “Social media is what I do best, and I started that Facebook page.”

Family members requested that anyone with information is asked to contact a tip line, which also accepts anonymous tips, at 800-551-3080 or www.elainepark.tips.

The Glendale Police Department, which is investigating the case, can be reached at 818-548-4911.