Two years later, their murders remain unsolved.
McCollum was 27 years old when she died on the pavement near the corner of 16th and Shotwell. At the time, she and Tennessee were living in a box around a cluster of tents and makeshift shelters that had popped up in the area.
McCollum's beloved pit bull, Lily, was found with her, covered in Lindsay's blood.
McCollum's mother, Carrie, says time hasn't eased the blow.
"It seems to make it worse," Carrie McCollum says. "I think before I was walking around in a fog and now I'm hit with the reality of it all, and the permanence of it."
Throughout her adult life, Lindsay struggled with heroin addiction and mental illness. Carrie says her daughter was living on and off the streets for three years leading up to her death.
But she wants people to know that the child she raised in the Central Valley city of Patterson was more than the negative stereotype many people have of an addict or homeless person.
"She was good, she was talented, she was smart, she loved animals," Carrie says.
Lindsay danced and played piano as a child. She loved to read. At one point, while she was doing well at a substance rehab program in San Francisco called Walden House, Lindsay led group trips to the library.
"She just lost her way," Carrie says. "But that doesn't mean she deserved what she got."
Carrie says that like any other person, her daughter deserves justice.
This summer, she began offering a $5,000 reward for information about Lindsay’s death. She had signs printed and put up on the corner near where Lindsay and Tennessee were shot.
"I felt like we were being forgotten and Lindsay was being forgotten," she says.
Evangelina Salazar, a long-time friend from the time Lindsay was 13, hung the reward posters in July.
"Lindsay did mean a lot to me," Salazar says. "Whenever she was around, everything just got lighter. There was something about her that put people at ease."
Salazar says nothing can change what happened to her friend, but wants the people responsible for the killings found and brought to justice.
"It doesn't matter if they were [living] on the street," she says. "They just didn't deserve to go that way. Somebody loves them. We love them."
The San Francisco Police Department confirmed that the case is still open and no arrests have been made.
Still, Salazar and Carrie McCollum hold out hope that someday, someone will come forward to shed light on what happened that December night.
"People do remember. It comes to them in moments of clarity," Salazar says. "Any little bit of information helps."
Carrie and her husband now live in Knoxville, Tennessee. She recently had a memory quilt made from the clothes and dance costumes she saved from Lindsay’s childhood.
She just got it back a few weeks ago.
"Every little piece of material I could see a flash of her when she was wearing it," Carrie says. "I asked the lady to make it very bright and happy, and she did a great job."
For the second anniversary of Lindsay’s death, Carrie flew back to California to visit her other daughter, Lindsay's sister — to spend time together and try to get through the day.
For information concerning the deaths of Lindsay McCollum and Eddie Tate, Lindsay's mother can be contacted at LindsayMcCollumsMom@gmail.com.