Cop Killer Christopher Dorner was Piers Morgan Fan and Gun Control Advocate

Christopher Dorner highlighted the problems with gun control in the US before going on his killing spree in California.

The former LAPD officer, who is believed to have been killed in a mountain cabin earlier this week, said he should not have been able to purchase the weapons he used for his rampage so easily.

Dorner, 33, wrote in his manifesto that he supports gun control and said his being able to purchase class III weapons without a background check shows that laws regarding guns need to change.

He heaps praise on Piers Morgan the British host of the CNN Tonight talk show, who has been outspoken about the need for gun control since the Sandy Hook massacre.

Dorner said Morgan should be given an "indefinite resident alien and Visa card", but said as a foreigner who comes from a country where guns are illegal, he cannot understand how US citizens feel about their right to weapons.

"I agree with you 100 percent on enacting stricter firearm laws but you must understand that your critics will also have in the back of their mind that you are native to a country that we won our sovereignty from while using firearms as a last resort in defence and you come from a country that has now legal private ownership of firearms."

Dorner killed four people and injured two more during his rampage, which began on 7 February.

The former officer said he would bring "warfare" to the LAPD in a bid to expose police corruption and clear his name.

Dorner said he was wrongfully dismissed from the force in 2008 after reporting that his senior officer Teresa Evens kicked a suspect who suffered from schizophrenia and severe dementia. He also alleged widespread racism within the LAPD.

In his manifesto, which he published online, Dorner said: "If you had a well regulated [automatic weapons ban], this would not happen. The time is now to reinstitute a ban that will save lives ... Why does anyone need a suppressor? Why does anyone need a AR15 rifle?

"This is the same small arms weapons system utilised in eradicating Al Qaeda, Taliban, and every other combatant since the Vietnam War.

"[Automatic weapons] do not need to be purchased as easily as walking into your local Walmart or striking the enter key on your keyboard to 'add to cart'."

Prior to joining the LAPD, Dorner was a US Navy reservist, who earned a rifle marksman ribbon and pistol expert medal.

He wrote: "All the firearms utilised in my activities are registered to me and were legally purchased at gun stores and private party transfers.

"All concealable weapons (pistols) were also legally registered in my name at police stations Federal Firearms License. Unfortunately, are you aware that I obtained class III weapons (suppressors) without a background check through National Instant Criminal Background Check System or Dealer's Record of Sale completely legally several times?

"I can buy any firearm I want, but should I be able to purchase these class III weapons without a background check and just a $10 notary signature on a quicken will maker programme? The answer is no. I'm not even a resident of the state I purchased them in. Lock n Load just wanted money."

Class III weapons include machine guns, short-barrelled rifles, short-barrelled shotguns, silencers and destructive devices, such as grenades.

"I hope you realise the small arms I utilise should not be accessed with the ease that I obtained them. Who in their right minds needs a f*****g silencer? Who needs a freaking SBR AR15? No one.

"Never again should any public official state that their prayers and thoughts are with the family. That has become cliché and meaningless. It's time for action.

"Remember the innocent children at Austin, Kent, Stockton, Fullerton, San Diego, Iowa City, Jonesboro, Columbine, Nickel Mines, Blacksburg, Springfield, Red Lake, Chardon, Aurora and Newtown. Make sure this never happens again."

In his manifesto, Dorner voices his support for Obama and the former president George W Bush.

"I agree with you 100 percent on enacting stricter firearm laws but you must understand that your critics will also have in the back of their mind that you are native to a country that we won our sovereignty from while using firearms as a last resort in defence and you come from a country that has now legal private ownership of firearms."

In his State of the Union address yesterday, Obama demanded a vote on gun control laws in the US.

While the charred body found inside the burned-out cabin has not been formally identified as Dorner, police say his driving license was found in the rubble.

Before the cabin was engulfed in flames, Dorner was involved in a police shoot-out, in which one officer was killed and another was wounded.

San Bernardino County Sheriff John McMahon said officers did not intentionally burn down the cabin. He said police shot pyrotechnic tear gas into the cabin and it erupted in flames.