Marcus Johnson's mother keeps photos and mementos of her youngest son as a reminder of his life and death.

It has been six years since he was gunned down near Dunbar High School in Northwest Washington, and his killing is the first of a three cold case videos that D.C. police detectives put up on YouTube earlier this month.

Police are hoping someone will see the videos and come forward with information that can help close the cases.

The four-minute videos open with music and video nearly similar to that of "Law and Order." A detective provides the basic outline of the case, and then some words from a family member.

"I miss him so much, sometimes I can't come into my front room because this is my pain room," Johnson's mother, Mildred Johnson says.

She says her son loved two things most: football and his older brothers. He was better at the sport than one brother who played professionally, but his life took a different direction, she said.

Marcus Johnson, 35, was shot and killed on May 1, 2006, at about 8:45 p.m. on the 1400 block of First Street NW.

She asks on the video for someone who saw something or knows something to come forward.

"It's only right that I have a place to go and say to Marcus, 'I can let you go. You're free now,' and I need that," she said.

Anyone with information is asked to call Det. Jeff Owens at 202-277-4239 or Command Information center at 202-727-9099. D.C. police offer a reward of $25,000 for information that leads to a conviction.