[2] Acquaintances say that Loughner's personality had changed markedly in the years prior to the shooting, a period during which he was also abusing alcohol and drugs.

He began to abuse alcohol and other drugs, including cannabis (marijuana), cocaine, psychedelic mushrooms, LSD, and Salvia divinorum (a hallucinogen legal in Arizona).

[4] In the months leading up to the shooting, Loughner's parents became increasingly alarmed at their son's behavior; at one point, they resorted to disabling his car every night in order to keep him at home.

[24] From February to September 2010, while a student at Pima Community College, Loughner had five contacts with campus police for classroom and library disruptions.

Some of his teachers complained to the administration about his disruptions and bizarre behavior, as they thought it a sign of mental illness and feared what he might do.

Several college classmates recalled an incident in which Loughner, during a class discussion, had mocked and laughed at a young woman who was describing her abortion.

[9] "(Loughner) started making comments about terrorism and laughing about killing the baby," former classmate Don Coorough recalled to ABC News.

This belief intensified after he attended her August 25, 2007, event when she did not, in his view, sufficiently answer his question: "What is government if words have no meaning?

"[19] Loughner kept Giffords's form letter, which thanked him for attending the 2007 event, in the same box as an envelope which was scrawled with phrases like "die bitch" and "assassination plans have been made".

[37] Zane Gutierrez, a friend, later told The New York Times that Loughner's anger would also "well up at the sight of President George W. Bush, or in discussing what he considered to be the nefarious designs of government.

[43] Some people who study right-wing militia groups and those who align themselves with the so-called Patriot movement said Mr. Loughner's comments on subjects like the American currency and the Constitution, which he posted online in various video clips, were strikingly similar in language and tone to the voices of the Internet's more paranoid, extremist corners.

", in reference to the United States national motto printed on coins and paper currency, "In God We Trust".

"[53] The MySpace page showed a close-up photo of a handgun sitting atop a document titled "United States History.

"[25] On January 8, 2011, at 7:04 a.m. MST, Loughner went to a Walmart store near the Foothills Mall to purchase ammunition, but left that store and completed his purchase at Walmart on North Cortaro Road at 7:28 a.m.[36][54] He was stopped by Arizona Game and Fish Department officer Alen Edward Forney at 7:34 a.m. for running a red light, but once the officer determined there were no outstanding warrants for Loughner, he was allowed to proceed to his destination with a warning to drive carefully.

[14][36] Loughner took a taxi to a Safeway supermarket location in Casas Adobes, where Rep. Giffords was holding a constituents meeting.

[56][57] Loughner opened fire on Giffords from close range, hitting her as well as numerous bystanders,[56][57][58] and killing six people.

[36] A photograph taken by the Pima County Sheriff's Office's forensic unit was released to the media on January 10, 2011[62] and published on front pages nationwide.

[69] The entire federal judiciary of Arizona recused themselves from hearing the case because of their ties to fellow judge John Roll, who was killed.

[72] Prosecutors representing the State of Arizona, which has concurrent jurisdiction in the matter, announced they intended to file murder and attempted murder charges on behalf of the victims who were neither members of Congress nor federal employees (although they could legally file charges on behalf of all victims, at their discretion).

[74] Loughner, whose hair had partially regrown since his arrest, smiled while presented with the charges related to the shooting, including the attempted killing of Giffords and two of her aides.

According to The New York Times, Loughner believed he succeeded in killing Giffords, and clashed with his lawyer when she informed him that the congresswoman had survived.

On June 26, 2011, Judge Burns ruled that prison doctors could forcibly medicate Loughner with antipsychotic drugs in order to treat him to restore him to competency for trial,[82][83] but on July 12, 2011, a three-judge federal appeals panel from the Ninth Circuit ruled that Loughner could refuse anti-psychotic medication, since he "has not been convicted of a crime, is presumptively innocent and is therefore entitled to greater constitutional protections than a convicted inmate.

[88] The request for an injunction was denied by the court, allowing treatment to continue pending a full hearing into the matter.

[91][92] In March 2012, a federal appeals court denied a request by Loughner's lawyers to halt his forced medication.

[93] On May 24, 2012, a federal judge ordered a competency hearing for June 27 (later postponed until August 7) to determine Loughner's mental fitness to stand trial.

[96] On August 7, 2012, Judge Burns found Loughner competent to stand trial based on medical evaluations.

Pima County Attorney Barbara LaWall declared later that afternoon that she would not prosecute Jared Loughner on behalf of the State of Arizona.

LaWall explained that her decision would afford the victims and their families, as well as the community in Tucson and Pima County, an opportunity to move forward with their lives.

She said that, after speaking and consulting personally with each of the surviving victims and with the family members of those killed, it was clear that they would not be benefitted by a State prosecution.

[107] As of 2015[update], Loughner is serving his life sentence at the Federal Medical Center, Rochester, Minnesota, a prison for inmates with specialized health issues.