Four years ago this week, a Northwest D.C. woman vanished from her home under suspicious circumstances. Pamela Butler was supposed to spend Valentine's Day with her mother, but never showed.
Police questioned Butler's ex-boyfriend, but there have been no charges and Butler's body has never been found.
The Butler family has never wavered from its theory that she was murdered and her body hidden in a place where it may never be found.
D.C. police continue to investigate the case, supervised by a veteran cold case prosecutor. But other than Butler's disappearance, there is no solid evidence of a murder, and her ex-boyfriend steadfastly denies having had anything to do with it.
Derrick Butler misses his sister terribly. For four long years, he has been the one out front, the one talking with police, the one talking with reporters, the one trying to make sure no one forgets about Pam.
"It's hard standing on this corner," said Derrick Butler in an interview Friday. "It's hard waking up every day thinking about it, thinking that something happened to one of your siblings and you just don't have any answers. It's hard."
The house on 4th Street, NW looks very different now; the new owner giving it a complete makeover.
At one time, it was a home meticulously kept by a 47-year-old federal worker with a state of the art security system.
When Derrick Butler learned his sister was missing, he took a look at what it recorded; footage that shows Pam Butler's ex-boyfriend and not much else.
"If you look at the cameras, she's seen going into the house," said Derrick. "Nobody else is ever seen coming up to the house. He's seen going into the house shortly thereafter and he's seen coming and going at all odd hours of the night. And at times, when nobody had heard from Pam, he's seen coming in and out of the house."
D.C. police searched the house from top to bottom and had control of it for months.
They also searched a park where Pam like to jog as well as Rock Creek Park, where investigators believe her ex-boyfriend may have been around the time she disappeared.
"It has not gone cold," said D.C. Police Homicide Commander Robert Alder. "We continue to investigate the case and will continue to investigate the case and hope to bring it to a conclusion."
When Pam Butler first went missing, Derrick confronted her ex-boyfriend with what he saw on the surveillance system and other troubling behavior.
"He denied having any involvement in Pam's [disappearance]," said Butler. "But in talking to him, he talked in past tense most of the time. I will never see her again. I wish I could see her again."
No one has heard from Pam Butler in the last four years although police say they had reports from people who claim to have seen her.
Derrick Butler though has no doubt his sister did not disappear on her own.
Police have questioned Butler's ex-boyfriend at least twice and searched his home. He still lives in the area.
On Saturday afternoon, friends and family will gather on 4th Street in front of Pam's old house and hold a vigil in her memory.