In the days leading up to his attempt to assassinate Rep. Gabrielle Giffords (D-Ariz.), shooting suspect Jared Lee Loughner researched political assassins and punishments he could face for murder, an examination of his computer has found.

The Internet-browsing history on Loughner's computer indicates that the 22-year-old visited websites that contained information on political assassins, solitary confinement and the process and effects of lethal injections, the Washington Post reported Wednesday, citing law enforcement sources close to the investigation.

Authorities seized the computer from Loughner's Tucson home just hours after the Jan. 8 shooting and finished analyzing it last week. Their findings, sources said, will help prosecutors make the case that Loughner knew that he could face consequences for the shooting.

"The impression investigators have is that he was trying to educate himself on assassinations and also research the consequences," one law enforcement source told the Post. Authorities would not offer official comments.

Loughner was arraigned Monday on one federal charge of attempted assassination for the shooting of Giffords and on two charges for shooting two of her aides. More federal charges -- likely including the option for the death penalty -- are expected for the deaths of U.S. District Judge John Roll and Giffords aide Gabe Zimmerman. He's also expected to face state charges.

The Arizona Republic is a member of the Politico Network.