Gerald Dean Metcalf must have wondered when — or if — San Diego police would knock on his door to ask him about killing a Pacific Beach man whom he met at Horton Plaza almost four decades ago. It took 37 years, and thanks to DNA evidence and modern fingerprint technology, police say the 1971 murder of Gerald Jackson, 27, is solved. Metcalf, now 61, is charged with stabbing Jackson to death when Metcalf was 24 years old. The knock on his door by San Diego Police Detective John Tefft occurred in August 2008, where Metcalf was living in a house with his wife in the 21000 block of Easy Street in Chandler, Texas, a town of 2,000 residents. Metcalf was extradited to California, and now resides in the downtown central jail on $1 million bail. He has pleaded not guilty and his preliminary hearing is set for Jan. 15 in San Diego Superior Court. The suspect in Jackson’s murder was named after a paid intern with the police department, Gabrielle Wimer, 24, was looking at the cold-case file and discovered that investigators had fingerprints from the murder scene. The prints run through the FBI’s database and matched Metcalf’s According to court records, during a visit to Metcalf’s home in Texas, the suspect told Tefft, a homicide detective with the department’s Cold Case team, that he was picked up by Jackson in Horton Plaza on Dec. 29, 1971, and taken to Jackson’s apartment in Pacific Beach. Jackson’s nude body was later found in his bedroom of his Hornblend Street apartment. He had been stabbed 55 times. Tefft learned that Metcalf was arrested in 1984 in Texas for murder, but a jury had acquitted him. Metcalf’s palm prints were taken in that 1984 arrest, and they matched the palm print found on Jackson’s recovered stereo in 1972. Authorities wanted to match the fingerprints and palm prints with Metcalf again, and Tefft obtained a warrant from a Texas judge to take the prints of the suspect. On Aug. 27, Tefft, and two Texas officials knocked on his door. Metcalf agreed to accompany authorities to a Texas sheriff’s station where his prints were taken again, but he wasn’t told initially it was a 1971 murder investigation. Metcalf was not under arrest, but he was asked if he knew Gerald Jackson or had a reason why his fingerprints would be in Jackson’s car or apartment. Initially, Metcalf said he had memory problems and could not recall anything that happened in 1971 in San Diego. He told Tefft he wanted to terminate the interview and go home, which he was allowed to do. Tefft asked him if he could phone him the next day, and Metcalf said yes. The next day, Metcalf’s wife answered the phone call from Tefft and he wrote that “she informed me the two of them talked throughout the evening” after he returned home. Tefft added, however, that she was given no details. When Metcalf talked with Tefft, he was quoted as saying “I never told anyone about what happened in San Diego. I never told my wife.” Metcalf agreed to be interviewed in person again. Metcalf then confessed to the slaying in a tape-recorded interview conducted by Tefft outside his home. Metcalf said he remembered being picked up by a man and taken to his apartment. Metcalf said he went with the man because he was “cold, tired and hungry.” He said he didn’t remember the man’s name. Metcalf said Jackson asked him to sleep in the same bed with him, and he agreed, telling the detective he took off his clothes and got in the bed with Jackson. Metcalf said Jackson tried to initiate sex with him, which he refused. Metcalf told the detective Jackson grabbed a knife and ordered him to perform oral sex. Metcalf claimed he was in “the fight of his life” and “blacked out” the details. Metcalf said he fled the apartment and took Jackson’s car keys. He spent the night in the vehicle, and remembers leaving it somewhere with the keys in it. When asked about pawing the victim’s stereo and taking his wallet, Metcalf said he did not remember. The detective showed Metcalf a copy of the handwriting on the pawn shop receipt, and even Metcalf said it looked like his handwriting. “They got the right guy. The issue is why did it happen,” said Metcalf’s attorney, Gary Gibson, to a reporter. “The guy tried to rape him. He was in shock. The issue isn’t who killed Mr. Jackson. It’s not a whodunit from 1971. It’s a ‘Why did it happen?’” Gibson said. Gibson said Metcalf was homeless in 1971 when he met Jackson and went home with him for that reason. Metcalf is not gay, Gibson said, and he says he acted in self-defense. Metcalf is now “an old, sick man,” the attorney said, adding, “He is on a liver transplant list.” Gibson said “a lot of the material witnesses are dead,” including many of Jackson’s friends but also police department officials who investigated the case. “I was amazed at the quality of the investigation (in 1971),” Gibson said. “It is the oldest case I’ve ever handled. It takes you back to a different time, different place.” Tefft asked Metcalf about the 1984 murder case brought against him in Texas that involved the death of friend fatally struck with a baseball bat. Metcalf said the jury acquitted him because he acted in self-defense.