Now a year later, there are only a few clues.
A suspect is still on the loose -- and a motive -- unknown.
Detective Gary Jones said, "It's been a tough year....and we still haven't gotten to the bottom of this."
Tonight Samantha Olson's family members fear this case will go cold.
Her sister, April Welshhons said, "It is getting to where it's a cold status and the less you pay attention, the more it's going to get colder and colder."
However, North Little Rock police still believe they will solve the murder of Samantha Olson, even though they have little to go on.
Meanwhile, people gathered tonight to remember Olson at the scene of the shooting on the corner of McCain and JFK.
Rev. Benny Johnson led the crowd in prayer.
It was an emotional event, as the vigil took place at the same spot an unknown person shot and killed Olson exactly one year ago today.
Those closest to her, reflected on a difficult year without a wife, mother, daughter and sister.
Eric Olson says being forced into the role of single father, after the murder of his wife, Samantha, was something he never fathomed.
He said, "And our little girl, she looks just like her mom and it's a piece of her with me every day in some small way."
A year after his wife's death, Olson still wears his wedding band.
He thinks about Samantha everyday, but his focus is on his little girl who is almost two years old now.
Olson said, "It's the gist of life right now. Everyday I have a routine. I get up taking care of Linea, going to the park and playing and doing that."
Olson is confident Samantha's murderer will be caught.
He says his daughter deserves to know what happened as she was riding in the backseat when the shooter killed her mother.
He said, "Someone who's willing to commit a crime like this, they're probably fairly ugly to most people in their life, and eventually someone is going to rat them out."
Near the intersection, where Olson was killed, her sister took a moment to reflect and remember today.
April Welshhons said, "It's not easy to talk about memories. It's funny sometimes, but then you end up in tears. You go home and you're like it's not supposed to be this way, it's not supposed be this way."
Welshhons says she's frustrated detectives haven't solved this crime.
For her, the possibility of an arrest is starting to fade, but she refuses to give up hope.
She said, "All we can do is get up every day and keep praying."
Detectives believe Olson's killer drove away in a maroon Ford F150 supercab.
If you know anything about this crime, call the NLR Police Department.
If you would like to follow Melissa Schroeder's reports on Facebook, you can click here and like her page.
Copyright 2015 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.