Washington, Jan 10 (Agencies): A note written by Jared L Loughner ahead of his shooting rampage on Saturday at Tucson in Arizona appears to show that he had planned to assassinate US congresswoman Gabrielle Giffords, a media report said.

Prosecutors charged Loughner, a troubled 22-year-old college dropout, with five federal counts on Sunday, including the attempted assassination of Giffords in connection with the shooting that left six people dead and 14 wounded, The New York Times reported.

Evidence seized from Loughner's home, about eight km from the shooting scene, indicated that he had planned to kill Giffords, Democrat of Arizona, according to documents filed in Federal District Court in Phoenix, the capital of Arizona.

Special Agent Tony M Taylor Jr of the FBI said in an affidavit that an envelope found in a safe in the home bore these handwritten words: "I planned ahead", "My assassination" and "Giffords".
Loughner, who is believed to have acted alone, is in federal custody and is scheduled to make his first court appearance before a magistrate judge in Phoenix on Monday.

Investigators focused their attention on Loughner, whom they accused of methodically planning shootings, which occurred outside a supermarket. The court documents said Loughner bought the semiautomatic pistol November 30 in Tucson.

The gun was legally purchased, officials said, prompting criticism of the state's gun laws, which allow the carrying of concealed weapons.

The documents also indicated that the suspect had previous contact with the congresswoman. A letter from Giffords was also found in the safe at Loughner's home, thanking him for attending a 2007 "Congress on Your Corner" event, like the one she was holding on Saturday when she was shot.

According to the report, Giffords was in critical condition after surviving.

Robert S Mueller III, the director of the FBI, said an intensive investigation was seeking to determine "why someone would commit such a heinous act and whether anyone else was involved".

Mueller added that discussions were under way to increase security for all members of Congress.
Capitol security agencies are planning to join the FBI Wednesday in a security briefing for members of Congress.

Already, the US Marshals Service has increased protection for federal judges in Arizona.

Mueller said additional state charges might be filed, and he did not rule out the filing of terrorism charges.