Family inconsolable after Brooklyn college student shot to death by mugger in BJ’s parking garage: ‘So sad and so frustrated’ (EXCLUSIVE)

A visit from Mayor Adams did little to console the mother of a 19-year-old college student killed in the parking garage of a Brooklyn BJ’s by a teen gunman who stole his backpack.

“She can barely think,” Joanna Tsoi said of her sister, the mother of victim Dereck Chen. “We feel like the city is having a lot of problems right now. Every day you hear about a murder. ...We need somebody to straighten it out.”

Tsoi, 51, said her sister is epileptic and has had multiple panic attacks since the Thursday shooting and was twice taken to the hospital.

“That’s why we are all here every day,” Tsoi said as relatives gathered at the victim’s Bensonhurst home Monday. “We’re trying to keep her — we need her to be around.”

Chen’s father is trying to remain strong as the family grapples with the unimaginable loss.

“He’s keeping his composure for her,” Tsoi said through tears. “But he was in the [family’s] garage, crying, breaking down. He’s trying to stay strong and help her, but it’s not easy.”

“We’re just so sad and so frustrated at how everything happened,” Tsoi added. “He’s just 19, he didn’t deserve this. He was in college, he was just starting his life.”

Chen and his three friends stepped into an elevator on the third-floor of the garage of BJ’s Bensonhurst wholesale store about 10:15 p.m. Thursday — and were confronted by the teen gunman.

Surveillance video obtained by investigators shows the crook yank a 9-mm. handgun from his waistband and pull back the slide, according to court papers.

The mugger snatched a fanny pack and two backpacks, one of them belonging to Chen, who fought back and was shot in the buttocks and upper body as the elevator reached the ground floor.

The shooter ran off, as did Chen’s panicked friends, but they quickly dialed 911. Suspect Edino Tzul was nabbed trying to jump into Gravesend Bay, located behind the BJ’s, infrared video released by the NYPD shows.

Tzul, 18, who has no prior arrests, at first claimed the gun belonged to the victim. He also, according to court papers, admitted shooting Chen. He was charged with murder and is being held without bail.

Adams, escorted by numerous marked police cars, visited Chen’s parents Saturday morning, but Chen’s grief-stricken aunt said she just wishes he could work to straighten out the senseless violent crime plaguing families across the city.

“What we have to do to keep our children safe? You cannot have so many families going through like this,” Tsoi said. “What is the point of living here if we are living in fear?”

Chen was about to start his second year at Kingsborough Community College and was working at Key Food, a pit stop on his way to what he hoped would be a career in finance and technology.

“At 19, a lot of times your friends just want to hang out and play,” Tsoi said. “But he’s actually working because he wanted to be independent. You’re talking about a really smart kid.”

Roberto Perez, a Key Food manager, said Chen started work at the supermarket a year ago as a cashier, left to focus on school and then came back to work during this summer. He last worked the day he was killed, his shift ending at 7 p.m., just over three hours before the shooting.

“As a worker, he always helped,” Perez said. “He was a good worker.”

A co-worker, Jasmine Yu, 20, said Chen “was easy to talk to, very funny.”

“He always did what was asked of him,” Yu added.