LOS ANGELES - Jared Lee Loughner on Tuesday pleaded guilty to 19 counts of charges including wounding former US congresswoman Gabrielle Giffords in Tucson, Arizona during the January 2011 shooting rampage, and the prosecution has agreed not to seek death penalty, local media outlets reported.

US District Judge Larry Burns found Loughner, 23, mentally competent during a hearing held at the court, saying: "My personal observations of him leave no questions in my mind that Loughner knows what's going on today," according to Azcentral.com.

US Attorney John S. Leonardo speaks during a news conference outside the US Federal Courthouse after a court hearing for Tuscon shooting rampage suspect Jared Loughner in Tucson, Arizona August 7, 2012.  [Photo/Agencies]

The suspect pleaded guilty to 19 of the 49 charges against him. He admitted that he planned to use his handgun to kill Giffords and others attending an event Giffords held for her constituents on January 8, 2011, outside a supermarket near Tucson.

The plea arrangement, struck between federal prosecutors and defense attorneys, comes after a prolonged legal wrangling over Loughner's mental capacity. The development is the latest in a string of sagas in the wake of a deadly mass shooting in Tucson, Arizona on January 8, 2011. The plea agreement sets the stage for a likely prison sentence of life without parole.

Six people including US District Judge John Roll and Giffords staffer Gabe Zimmerman were killed and 13 others were wounded.

During the hearing, Dr. Christina Pietz, Loughner's forensic psychologist, testified that she believed Loughner was competent to stand trial after spending months in a prison psychiatric hospital in Missouri. According to Pietz, Loughner wanted a job since his imprisonment, which Pietz said was a sign for competency. Pietz concluded she believed Loughner to have a factual, rational understanding the role of jury, a judge, prosecutors and judicial proceedings.

The suspect also expressed shock that Giffords survived, according to Pietz. Loughner told her he was disappointed that he failed to kill Giffords.

Questions about Loughner's sanity arose after the massacre happened. Psychological evaluation found the suspect incompetent to stand trial. The man was accused on 49 counts, including several which could be punishable by death, if he were convicted.

The plea agreement carries multiple life sentences, his lawyer Judy Clarke was quoted by the media outlet.

The suspect will be sentenced on November 15.