Police in California have arrested a man believed to be the "Golden State Killer", apparently solving a notorious decades-old mystery over the identity of the man behind dozens of rapes and multiple murders in California in the 1970s and 1980s. Joseph James DeAngelo, 72, is being held in the Sacramento County jail on two counts of murder. DeAngelo was once a policeman, who was reportedly fired from Auburn police in 1979, accused of stealing a can of dog repellent and a hammer from a Sacramento shop. The city manager was quoted in a newspaper article as saying that DeAngelo was dismissed after he “failed to answer any of the city’s investigations and did not request an administrative hearing.” At one point back in the 1970s, DeAngelo asked his brother-in-law what he thought about the crime spree committed by the person then best known as the East Area Rapist, Oxygen.com reported. Police and television crews at DeAngelo's house in Citrus Heights, California Anne Marie Schubert, Sacramento County district attorney, was joined by officials from across the state and relatives of victims on Wednesday to announce that DNA evidence developed in the past six days had led to his arrest. She added that he had lived for more than three decades on a quiet suburban street in Citrus Heights. Neighbours said that DeAngelo had been living in the neighborhood for 30 yeas and described him as a “relatively nice guy” who was prone to “cursing outbursts you could hear down the street.” The Golden State Killer, also known as the "East Area Rapist" and "Original Nightstalker," is suspected of carrying out at least 12 murders and 45 rapes in California between 1976 and 1986, according to the FBI. The Golden State Killer was the subject of "I'll Be Gone in the Dark," a best-selling book by Michelle McNamara. McNamara died two years ago at the age of 46 but her book helped spark renewed interest in the case. Sacramento County Sheriff Scott Jones, left, talks to reporters about the arrest Joesph James DeAngelo, seen in photo, on suspicion of committing a string of violent crimes in the 1970s and 1980s DeAngelo is believed to be originally from Bath, New York. He served in Vietnam after graduating from Folsom Senior High School in June 1964 and on his return competed an associate’s degree with honors in police science at Sierra College. He then graduated from California State University at Sacramento with a degree in criminal justice. At some point, he had also interned with the Roseville Police Department.