FOREST HILLS, Queens (PIX11) – The search continues for the person behind the shooting death of a delivery worker in Queens, but police say they are now looking into a potential suspect.

For now, all police can offer is comfort until they find 45-year-old Zhiwen Yan’s killer. The NYPD’s First Deputy Commissioner Edward Caban, members of the department’s liaison unit and members of the mayor’s office showed up to meet Yan’s family and show his wife support.

“It was devastation. When you look in her eyes and the first thing she tells me is, ‘catch him, catch him,’ as a human being, it touches you,” Caban said.

The Forest Hills community is also mourning Yan’s death. Just days after he was gunned down while on a delivery run, community members are still leaving their thoughts and prayers at the Great Wall restaurant where he worked for ten years. The restaurant has been closed ever since the shooting. The owner said he feels lost because Yan was more than just an employee.

“We have been together ten years. We were like a family really,” said Kai Yang.

Sources told PIX11 News police are zeroing in on a disgruntled customer who allegedly argued with employees at Great Wall over duck sauce. The arguing went on for months and escalated to the owner’s car being damaged. That same customer apparently pointed a gun at employees at one point, sources said, but no one expected Yan would lose his life.

Yan’s brother James Zhao said the most important thing to the family “is to catch the killer” because they “don’t want the same thing happening again.”

Yan’s family also has to navigate without him. He was the sole breadwinner and worked multiple jobs. The NYPD is making sure they are not alone, especially Yan’s three children.

“Whatever we can do, little things, services for the children,” Caban said.

There is a growing memorial at the Great Wall restaurant where Yan worked so many hours to provide for his family. The family has created a GoFundMe page for people to donate to support them through this difficult time.