Rewind to the Crime: Who shot Christopher Adams?

Monday marks three years to the day since Christopher Adams was shot to death during what investigators say was a robbery gone bad.

His killing in northwest D.C. concluded with a quick arrest, and the suspect, Glenn "Spook" Walker was charged with first-degree murder while armed. But just days before the trial, the case--which appeared solid-- collapsed. Walker's charge was dismissed, and he was set free.

The case against Walker, known to many as "Spook," had come together fast. A witness who was in the block to buy drugs told police Spook was standing closest to the black Geo Prism when they heard a shot--and then two more shots.

The witness was sure it was Spook who had fired the shots, telling detectives that after the shooting, Spook ran with others into 812 Jefferson Street-- where the accused killer later came into the lobby to sell some drugs.

A court document in the case says the witness was "110 percent sure" it was Spook and picked him out of a photo lineup. But 15 months later, Spook was released from jail--even after prosecutors secured and indictment in the case.

"Our standard in proceeding to trial is that we have to be convinced that we have a reasonable chance at success on the merits, and based on some late breaking developments in that case, we did decide that the wiser course was to move to dismiss without prejudice and take a step back to investigate the case," said Assistant U.S. Attorney Glenn Kirschner.

On the night he was killed, Christopher Adams had just dropped off one friend and was just about to drop off another when he came to a stop in the intersection of 8th and Jefferson Streets NW. A witness says he was then surrounded by four individuals. One of them got into the left rear passenger seat and opened fire, hitting Adams in the back of the head.

That's when Adams' friend, who was sitting in the front passenger seat, bolted toward Kennedy Street NW, where he found two officers sitting in a cruiser.

Kirschner and the detectives who investigated the murder thought they had a solid case of a robbery gone bad, but in June 2016, they realized it was falling apart. And then came the moment they had to tell Adams' mother, Tawana, that the suspect in the case was being let go.

"It's heartbreaking," said Kirschner. "It is extraordinarily painful for the entire team-- the detectives and the prosecutors-- but all of that pales in comparison to what Tawana suffered as a result of where we were with the case at that point in time."

"Lil' Chris," as Adams was known, has been gone for three years--and it's a loss his mother says she feels every minute of every day.

"He wasn't just everything to me," Tawana Adams explained. "He was everything to everyone. You know, he was a well-known kid, he was a well-known, loved kid. He was the most improved student at Wilson."

Adams played football and basketball at Wilson High School before going off to Allegany Community College in Cumberland.

"For me as a grandmother, to see my daughter cry because someone killed her son, and then it comes back to me because we are all blood," Janice Taylor, Adams' grandmother said. "He is no longer here, but go to sleep at night, I can't rest because Christopher is on my mind."

In the days after Walker was released from jail, Tawana Adams began putting up posters about her son's murder on poles along Kennedy Street NW--and it was outside of Tony's Carryout that she came face to face with Spook.

"And we looked at each other like this for a second, two seconds-- and then I just, actually just had to go to my car. Just walked straight to my car and I just had to pray," Adams' mother said.

FOX 5 tried to find Glenn Walker to get his side of the story, but a number listed in his name has been disconnected. No one came to the door at the address listed for him in court records.

"This appeared to be a robbery gone bad. Christopher Adams was an entirely innocent victim. He was not participating in anything that would have resulted in him being robbed," said Kirschner.

Although the case was not strong enough to go to court, there is this: a court document filed in the case says Walker told police he was at the scene that night, and that he was standing next to Adams' car when the shots were fired--but that the gun was in someone else's hand.

Prosecutors declined to comment on the specific evidence in the case, but said they are still hard at work on it.

Adams was home on spring break on the night he was killed, and he had just laid down a new track with friends at a recording studio in Hyattsville. That song is now the ringtone on his mom's phone.

"I miss my son," she said. "I miss my son period. If I can't have my son…. I just miss my son. I just really miss my son."

Anyone who can identify the people who were seen standing around Adams' car on the night he was killed is asked to call the Metropolitan Police Department at (202) 727-9099. A reward of up to $25,000 is offered for information leading to an arrest and conviction in the case.