For a whole year, Nellie Martinez wore nothing but black, whether it was to work, church or anywhere else.

"I was in luto (mourning)," said Martinez.

She had good reason to mourn. It was May 10, 1990, when her 4-year-old daughter, Jessica Martinez, vanished while playing right outside her family's apartment in the 5000 block of Belle Terrace at what was then called Timber Cove Apartments. Eleven days later, her body was found buried in a cotton field at Bear Mountain Boulevard and Ashe Road.

This month marks 27 years since Jessica's disappearance and murder. Her case remains unsolved. Who would do this? And why? These questions and others continue to torment Nellie Martinez.

"I always say, 'Why can't police find the killer? What is the reason? What is the missing piece of the puzzle?'"

She sounded relaxed as we talked on her patio the other day.

It wasn't always that way. For years, Nellie would break into tears when she mentioned her daughter's name and it was difficult to carry on a conversation with her as she was overwhelmed with emotion.

Twenty-seven years is a long time to wait for police to call with the news that the person responsible for your daughter's murder has been caught. But Nellie is not the kind of woman who has idly stood by. As she puts it, she is a thorn in the side of police, keeping the pressure on the Bakersfield Police Department to keep the case from being forgotten.

Numerous detectives have been in charge of the case, each hoping to find something that others may have missed.

"It's still an open case and we're still very much dedicated to it," said BPD Detective Christopher Feola, who is now the lead detective on this unsolved mystery. "I'm very much dedicated to it."

Thing is, detectives can only dedicate so much time to unsolved murder cases. They also must deal with current ones. Nellie would like to see the BPD ask an outside agency to work with it on Jessica's case or establish a unit whose sole focus is to work on cold cases.

So a few years ago, she approached the Kern County District Attorney's office for help. The office has been receptive.

To begin with, the DA's office has expanded the search for suspects by looking at similar crimes committed in other parts of the state going back 10 years before and after Jessica's disappearance.

"We could always be looking at someone not native to Bakersfield," said Andrea Kohler, supervising deputy district attorney for special prosecutions.

So far the only person of interest in the case has been Christopher Lightsey. A convicted sex offender, Lightsey lived in the same apartment complex as the Martinez family, just a few yards away from its unit when Jessica disappeared.

However, DNA found on Jessica's shoe did not match that of Lightsey, who is on death row in an unrelated murder case. But there is something new about to be tried.

It's called GlobalFiler. Obtained in April by the Kern Regional Crime Lab, GlobalFiler is new technology that greatly expands DNA analysis to get an enhanced profile of a suspect.

"This gives us more information for identification purposes," said Garett Sugimoto, lead DNA technician with the crime lab.

Kohler admits coming up with a match always remains a challenge as a comparison sample is needed. It appears the new method will be tried on Lightsey.

So much time has gone by. People who may have information about the case could have moved on or died. Is this case still solvable?

"I think it is," said detective Feola. "I can't say it's going to be solved tomorrow or in a year. I just think it's people coming forward and giving us information and us re-talking to people."

May remains one of the toughest times for Nellie Martinez and her son, Rudy Martinez. He was just 8 years old when his sister was taken.

For a long time, he felt guilty about Jessica's disappearance. Both were playing outside when she vanished, and Rudy felt he should have kept a closer eye on his little sister.

May 10 is also when many Mexican families celebrate Mother's Day.

"It's a dark day for us," said Nellie. "It's a dark day for Rudy and me."

Anyone with information about this case -- no matter how minor — is urged to call Detective Christopher Feola at 326-3513. To remain anonymous, one also can call the Secret Witness line at 322-4040.

Contributing columnist Jose Gaspar is a news anchor for KKEY, Telemundo Bakersfield. Email him at His work appears here every third Monday; the views expressed are his own.