Samuel Little, was found guilty of three killings in 2014, has admitted 90 murders dating back to 1970 in exchange for moving to a new prison, said the Federal Bureau of Investigation in latest report.

The 78-year-old is deemed to be among the most prolific serial killers in US criminal history, while State and federal agencies are on way to match his confessions with the fatalities of dozens of females across the country from 1970 to 2005.

According to investigators, the United States’ serial killer has been already connected to 34 murders, while Little is experiencing life in prison after being sentenced in 2014 for the killings of three women.

The police had been taken into custody in September 2012 when he was discovered at a Kentucky homeless shelter and brought California where he was wanted on a drugs charge. Since then, United States’ one of the dangerous persons has been experiencing jail, though investigators have taken DNA samples from Little were that time associated to the unclear deaths of three women in Los Angeles county in 1987 and 1989.

Most dangerous United States serial killer murdered three of those victims by beating and strangling badly as it is being revealed under the investigations. Nonetheless, the bodies of these three female victims were dumped separately.

Mr. Little has appealed not guilty at trial, although was ultimately sentenced to three following life sentences having no chance of parole. On other side, the murderer of 90 carries an extensive criminal record including three women deaths, other offences contains armed robbery and rape.