By CBS3 Staff

NORRISTOWN, Pa. (CBS) — Sources tell Eyewitness News that police in Norristown are interviewing a family member of a possible person of interest in a hit-and-run that killed a Vietnam veteran on Sunday night. On a day meant to honor veterans, the family of a Montgomery County Vietnam veteran is grieving after 69-year-old Samuel Jackson, a Marine, was killed in a hit-and-run.

It happened just before 6:30 p.m. Sunday at West Oak and Astor Streets.

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The family wants the driver who struck and killed Jackson to do the right thing — turn themselves in. The Norristown community is emotional over the loss.

Credit: CBS3

Family and loved ones have made a makeshift memorial outside the victim’s house where the crash happened.

“How can you carry a burden like that around for the rest of your life? Knowing that you killed somebody that was loved,” said Peggy Jackson, Samuel’s sister.

Little Sammy, as sister lovingly called him was a Vietnam War veteran. She says war changed the Marine and he was never the same after he returned home.

“He would hear fireworks, he would hear thunder and it was shellshock. He was very standoffish,” Peggy said.

Jackson’s family is still in shock more than 24 hours after he was killed.

“Why didn’t you stop? Because you knew you hit somebody,” said Jessica Guidici, the victim’s stepdaughter. “Why didn’t you stop and make sure he was OK?”

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Jackson, a loving father and grandfather, was struck by a car outside his Norristown home and left for dead. On Monday, police say they believe the driver that killed Jackson was speeding.

Jackson’s 16-year-old grandson says he looked up to Jackson because of his service in the Marine Corps. Jackson proudly displayed a Marine sticker on the back windshield of his car.

“He served his country. He was a veteran,” Jayden Guidici said. “For now on, the stuff I do is for him.”

Jackson’s longtime girlfriend is pleading for this killer to come forward.

“You’re gonna get caught. No matter who did it, you’re gonna get caught, because I’m gonna be at the police station every day nagging and nagging and find whoever did this. I want justice. I will not rest until I get justice,” Debbie Campbell said.

As police continue to search for the driver, the family is preparing to bury a man who fought to keep our country safe.

“He was somebody, and it’s ironic that all this is being talked about on Veterans Day. He loved being a veteran,” Peggy said.

Investigators say security video captured a red Ford Focus leaving the scene.

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CBS3’s Matt Petrillo and Kimberly Davis contributed to this report.