FALLBROOK - He doesn't know her name. He'll probably never meet her. But Jimmy Johnson credits a 12-year-old New York girl with helping thaw the long-cold investigation into the 1984 slaying of his grandmother.

"There's no doubt about it, she's a hero," the 47-year-old Fallbrook cabinetmaker said.

Court records show that the girl turned in a man in 2005 whom she accused of sexually abusing her. If she hadn't done so, authorities would have no reason to take a DNA sample from the suspect, Craig Minggia, 47, of the Bronx. And they never would have matched his DNA with that found at the scene of 79-year-old Lillian Johnson's slaying in Worcester, Mass.

Because she did, the match was discovered. An ice-cold case, one the family had "written off" but not forgotten, Johnson said, got a blast of heat.

Detectives and the district attorney in Worcester went into high gear, collecting evidence that led to a search warrant. On Dec. 11, New York City police arrested Minggia -- who had been living in the apartment above Lillian Johnson at the time of her slaying -- on suspicion of murder. Now, he's facing extradition to Massachusetts to stand trial.

But even with the arrest, questions linger.

Investigators believe Minggia will fight extradition and the process of obtaining a governor's warrant will then have to start. While the extradition can be just a formality, in certain cases legal snags can delay the process or even prevent it.

Citing the uncertainty of extradition, Donald Johnson of Encinitas - Lillian's son, Jimmy's father - declined to be interviewed for this story. His son said the retired Camp Pendleton Marine and U.S. marshal remained nervous that the case, achingly close to closure, could slide back into the unsolved file.

But Jimmy Johnson said he decided to go public now to offer hope to others.

"I just want (other crime victims' families) to know that technology has changed, so don't give up," he said. "We'd given up and boom, look what can happen."

"Long bottled up"

At about 10:30 a.m. on July 16, 1984, Lillian Johnson's son Robert went to her apartment to make sure she had her breakfast. He found a blood trail and his mother dead in her bedroom.

Across the country, Jimmy Johnson, then 24, was at work in Vista. Jimmy was called aside by his boss, and told to go see his mother. She was at work, at an Oceanside bank. Mother and son walked to the beach. She delivered the news.

"It didn't register at first," Jimmy Johnson said. "But when we flew back for the funeral, that's when reality hit hard."

The woman he and his sister had stayed with every summer throughout childhood, who cracked them up with practical jokes, had been slain.

Through the years, Jimmy Johnson said he "bottled up" thoughts of his grandma. The pain was too intense. But he thought of her killer often.

"I wanted him to go to the death penalty right away once they caught him," he said. But over 24 years, even those angry thoughts faded as leads dried up. Resignation set in, he said.

But law enforcement officials never lost sight of the case. Two of Jimmy Johnson's cousins grew up to be police officers, one in Worcester, the other in nearby Sterling, Mass. Another cousin grew up to a lawyer in the Massachusetts attorney general's office.

They helped keep the case on detectives' radar, Jimmy Johnson said. But careful police work at every stage of the case made the arrest possible.

Blood work key

Minggia, who lived in the third-floor apartment above Lillian Johnson, was a Clark University student at the time of her slaying. He was interviewed by detectives as part of the original investigation, part of a routine neighborhood canvass, and his information was placed in a file, according to a history of the case recently published in the Worcester Telegram & Gazette newspaper.

Detectives collected evidence from the crime scene. Blood samples of the victim and the suspected perpetrator were collected and preserved. The samples ended up back with Worcester police and then were transferred to the Massachusetts State Police Crime Laboratory in 2002, the story said.

While reviewing the case file on Lillian Johnson's death, a police lieutenant called the crime lab in February 2004 and asked the DNA profile of the suspected perpetrator. The blood sample was placed into the Combined DNA Index System. At that point, authorities had no suspects in the case.

Two years later, Minggia emerged as a prime suspect, thanks to a match found with the perpetrator's stored DNA.

The 400-pound registered sex offender was arrested Oct. 20, 2005, in connection with sex crimes alleged by the 12-year-old-girl, who wasn't named in court documents because she's a minor.

Last May, Minggia was convicted of the crime and sentenced to 10 years of probation. Because of that conviction, he had to give New York authorities a DNA sample.

That sample, authorities said, matched the sample taken from the 1984 stabbing death of Lillian Johnson. Worcester police were told about the match on Dec. 5.

Jimmy Johnson was riding his motorcycle in the North County hills that day when he got a call on his cell phone from his father.

"It's not a done deal but they got a hit on the DNA," his father told him.

"I was thrilled," Jimmy said. "But it also drummed up some emotions that had been packed away for a long time."

He said his family was extremely grateful for all the officials - past and present - who investigated the case.

But the joy of having justice within their reach is tempered a bit.

"There's some sadness because a little girl paid a price for this to happen," he said. "She paid a price to bring this guy to justice."

Johnson said his relatives in law enforcement would try to get access to her address and send a thank-you letter signed by the entire family.