Why The FBI Undercovered John Walker's Explosion?

In 1968, the United States (U.S.) Navy was changed. The metaphorical fist of espionage began to jab Navy communications and formed a massive hemorrhage of information compromised. John Walker was mastermind behind it all. Between 1968 and 1984, Walker was the top spy for the Soviet Union. For 17 years, Walker was untouchable. The Navy was enormously damaged by his espionage. Secretary of Defense Caspar Weinberger concluded the Soviet Union made significant gains in naval warfare were attributable to Walker’s spying. His espionage provided Moscow “access to weapons and sensor data and naval tactics, terrorist threats, and surface, submarine, and airborne training, readiness and tactics,” according to Weinberger (Prados, 2014) I will explore
The FBI searched his home and found documentation of his spy ring. They found records of payments to "D" (Jerry Whitworth), who turned himself in to authorities in June. The FBI arrested Arthur soon after. (Prados, 2014)
In exchange for limits to his charges, John Walker made a deal to discuss his espionage in detail and plead guilty, and Michael also copped a plea. Arthur Walker was tried in August and found guilty. Whitworth went before a court in the spring of 1986. Whitworth received a $410,000(US) fine and 365 years in prison. Arthur was sentenced to three life terms plus a $250,000 fine, John received a life term, and Michael 25 years. In February 2000, Michael Walker was released for good behavior. (UNITED STATES of America, Plaintiff-Appellee,v.Jerry Alfred WHITWORTH, Defendant-Appellant.,
Linkov had a number of successful recruited sources. Besides John Walker, he also recruited an American journalist and a diplomat from Chilean. John Walker was his most prized possession of spy’s. Although Linkov and Walker only met on several occasions in Virginia, Casablanca and Vienna, Walker was the only reason Linkov received promotions within the KGB. He provided Walker with written specific detailed information on dead drops in the D.C. and Maryland area for 17 years.
John Walker and family destroyed the Navy’s communications systems programs. The Walker spy ring, also compromised the Navy's theater cipher settings. These settings estimated to decode over one million cryptographic messages of technical characteristics of the Navy’s systems. This enabled the KGB and its allies to develop countermeasures against the Navy. If the U.S. decided war was inevitable, Russia strongly believed they would have won. Today over one billion dollars have been spent to replace the equipment that was compromised by the