FRANKLIN—Porthia Douglas-Vaughn was just feet away when her 28-year-old son, Darrin Lee, was gunned down outside their home in Southampton Meadows mobile home park Thursday night.

“I couldn’t open the door,” she said Tuesday. “I was just so broken. Shattered.”

Jamar Douglas, Lee’s brother, went outside and found his brother. Twenty minutes after he was shot, Lee died from a gunshot wound to the head, according to police.

Three Suffolk men were arrested and charged with first-degree murder in connection with Lee’s death. They are Darrin L. Robinson, 20; Bruce L. Boone, 18; and Dayquan Eley, 18. Police on Tuesday said the shooting and the motive behind it remain under investigation.

Douglas believes the shooting occurred when the trio attempted to rob Lee.

“I guess people thought he had more than he had,” Douglas said. “I don’t know why they would want to try to rob him like that.”

The murder victim’s mother said Lee helped everyone, and she can’t understand why her son was killed.

“I have searched my heart, my soul in and out to figure out why anybody would want to kill him,” Douglas-Vaughn said. “It’s overwhelming, just to know that somebody would come to his home and just kill him.”

Lee was preparing to move to Georgia, and even had job interviews lined up for this week, Douglas said.

Andrea “Tookie” Jones, another of Lee’s brothers, said Lee was “an excellent father” to his 3- and 4-year-old sons.

Douglas described Lee as an “all-around good guy” and a “mediator.”

“If people had problems, he tried to get them to squash it,” Douglas said.

Lee’s family is still staying at the home in Southampton Meadows where he was gunned down but hopes to leave soon.

“I want to move as soon as possible,” Douglas-Vaughn said. “I hope and pray that God can help me find somewhere else to go because the memory is just too bad there.”

Family members said they want Lee to be remembered for the good he did during his short life.

“He was a loved child,” Douglas-Vaughn said. “A child sent by God.”