'Son of Sam' Recounts the 'Battle Going on Inside My Head' in First TV Interview in a Decade

David Berkowitz, the infamous serial killer known as the "Son of Sam," has admitted that he was lost during his reign of terror in New York City, in an interview airing on the 40th anniversary of his capture.

Read: 40 Years After 'Son of Sam' Arrest, Detective Reveals How Cops Finally Ended His Reign of Terror

From July 1976 to July 1977, Berkowitz’s .44 caliber killing spree left six people dead and seven others wounded in eight separate attacks across the Big Apple.

Speaking to CBS News, Berkowitz claimed he was feeling "isolated" as he committed the heinous attacks.

"I didn't see it at the time," Berkowitz said from behind bars at Shawangunk Correctional Facility in upstate New York. "I was just very lost and confused. There was a battle going on inside me."

Berkowitz has been a resident of the maximum security facility since April 2016, when he was transferred from Sullivan Correctional Facility.

In a new CBS special, Son of Sam │The Killer Speaks, airing Friday — 40 years to the day after he was finally taken into custody — Berkowitz said the shootings were "a break from reality. [I] thought I was doing something to appease the devil. I'm sorry for it."

He added: “I see that people will never understand where I come from, no matter how much I try to explain it," he added. “They wouldn't understand what it was like to walk in darkness."

His interview with CBS is the first time he has spoken out on television in more than a decade.

Berkowitz, 64, also said he wished he could drop the “Son of Sam” moniker that has been placed over his name for the last four decades.

“That was not me," he said. "Even the name, I hate that name, I despise the name. That was not — that was a demon."

After his arrest, Berkowitz told police he claimed he had been given orders to kill by his neighbor’s dog, the black Labrador retriever he’d once shot. The dog survived with the bullet lodged in its backside.

On May 8, 1978, Berkowitz pleaded guilty to six of the murders and was given six consecutive 25-years-to-life sentences.

Read: How 'Son of Sam' David Berkowitz Went From Following the Devil to God

He has been denied parole every time he has been eligible, most recently in June 2016. His next parole hearing is May 2018.

Berkowitz has converted to Christianity, something he has said he has done since the late 1980s after he was transferred from Attica State Prison to Sullivan. 

He now goes by the moniker "Son of Hope."

Watch: In the Footsteps of a Killer - Revisiting the 'Son of Sam' Murders