The FBI and Chicago area police are turning their attention back to the unsolved 1982 Tylenol killings. The crimes left seven people in and around Chicago dead after the victims unknowingly took Tylenol poisoned with potassium cyanide. DNA samples are being sought from numerous potential suspects, including Ted Kaczynski, otherwise known as the Unabomber.

Chicago FBI spokesperson Ross Rice says new technology could yield new insight. “There’ve been tremendous strides as you know in forensic evidence since 1982. We have new investigators that are looking into interviews that were conducted, witness statements and just trying to determine if this case can be brought to its conclusion,” he said.

The Unabomber has so far declined to voluntarily give samples of his DNA for the case, according to FBI spokeswoman Cynthia Yates.