TUCSON, Ariz. » The 22-year-old man accused of trying to assassinate U.S. Rep. Gabrielle Giffords in a deadly shooting rampage wrote "Die, bitch" in a note found at his home, a sheriff’s official said yesterday.

Investigators believe Jared Loughner’s handwritten message was a reference to Giffords, Pima County Chief Rick Kastigar said. It was found in a safe alongside other ones, including "I planned ahead," "My assassination" and the name "Giffords."

Authorities also revealed other new information about the hours leading up to the Saturday shooting that killed six people and injured 14 others, including Giffords.

That morning, Loughner’s father saw him take a black bag out of a car trunk, Sheriff Clarence Dupnik said.

The father approached Loughner, and he mumbled something and took off running, Dupnik said. The father got in his truck and chased his son as he fled on foot.

Loughner took a taxicab to the supermarket where the three-term Democrat was holding a meeting to hear the concerns of her constituents, authorities said earlier. Among those killed were a federal judge and a 9-year-old girl.

For all of it, Loughner’s parents, silent and holed up in their home since the shooting spree, apologized yesterday.

"There are no words that can possibly express how we feel," Randy and Amy Loughner wrote in a statement handed to reporters waiting outside their house. "We wish that there were, so we could make you feel better. We don’t understand why this happened.

"We care very deeply about the victims and their families. We are so very sorry for their loss."

The apparent target of the attack, Giffords, 40, was able to breathe on her own yesterday at an intensive care unit here, another hopeful sign of her progress, doctors said.

Meanwhile, the southern Arizona city shattered by the rampage prepared for an evening memorial service and a visit from President Barack Obama today.

In addition to the new details about the hours before the shooting, interviews yesterday with those who knew Loughner or his family painted a picture of a young loner who did try to fit in.

Before everything fell apart, he went through the motions as many young men do nowadays: living at home with his parents, working low-wage jobs at big brand stores and volunteering time doing things he liked.

None of it worked. His relationship with his parents was strained. He clashed with co-workers and police. And he could not follow the rules at an animal shelter where he spent some time.

One close high school friend who requested anonymity to avoid the publicity surrounding the case said he would wait outside 10 minutes for Loughner to leave the house when they were going out. When Loughner would get into the car, he would say that it took so long because his parents were hassling him.

The parents of another close friend recalled how Loughner’s parents showed up at their doorstep in 2008 looking for their son, who had left home about a week before and broken off contact.

While the friend, Zach Osler, did not want to talk with the AP, his parents, Roxanne and George Osler IV, did.

With the Loughners at their house, Zach Osler told them the name of the local hotel where their only child was staying, George Osler said. Loughner moved back in, he said.

Loughner, now 22, would come over several times a week from 2007 to 2008, the Oslers said.

The boys listened to the heavy-metal band Slipknot and progressive rockers the Mars Volta, studied the form of meditative movement called tai chi and watched and discussed movies.

Loughner’s favorites included little-known conspiracy theory documentaries such as "Zeitgeist" and "Loose Change" as well as bigger studio productions with cult followings and themes of brainwashing, science fiction and altered states of consciousness, including "Donnie Darko" and "A Scanner Darkly."

Even in small talk, he struck the Oslers as unusual.

"He always said, ‘Hi, Mrs. Osler. How are you today?’ When he left he made a point of coming over and saying, ‘Thank you for having me over,’" said Roxanne Osler, noting that was not typical for Zach’s friends. "Jared struck me as a young man who craved attention and acceptance."

Linda McKinley, 62, has lived down the street from the Loughner family for decades and said the parents could not be nicer — but that she had misgivings about Jared Loughner as he got older.

"As a parent, my heart aches for them," she said.

She added that when she was outside watering her plants, she would see Loughner riding down the street on his bike, often talking to himself or yelling out randomly to no one.

Once he yelled to some children on the street, "I’m coming to get you!" McKinley said.