Neighbors Junior Soto left, and Phillip Tafoya, both 12, check out the media at the Loughner home. The Sheriff's Department released reports Wednesday of the department's previous contacts at the home. ROSS D. FRANKLIN / THE ASSOCIATED PRESS

Hours before the mass-shooting Saturday morning that left six people dead and U.S. Rep. Gabrielle Giffords critically injured, the suspected gunman was pulled over for running a red light, went to Walmart twice and had a confrontation with his father, officials said.

The Pima County Sheriff's Department also released reports Wednesday of previous contact the department had at Jared Lee Loughner's northwest-side home.

One of the last stops for Loughner Saturday morning was at his home, where he mumbled something to his father as he stormed away with a black bag, said sheriff's Bureau Chief Rick Kastigar.

"I don't know that it was a confrontation between them, but the father did question what his son was doing outside," Kastigar said.

Randy Loughner, Loughner's father, told investigators that he found his son near the front of the house Saturday morning removing a black bag from the family's vehicle. He had concerns about what his son was doing and about what he had in the bag, Kastigar said.

"The father asked him something along the lines of 'What are you doing?' or 'What's in the bag?' " Kastigar said.

Loughner then mumbled something and quickly walked away, Kastigar said.

The father got in his vehicle and drove out to look for his son, said sheriff's Capt. Chris Nanos, but he never found him.

Jared Loughner later took a cab to the Safeway at North Ina and West Oracle roads, where officials say he opened fire, killing six people and injuring 13.

Loughner was charged Sunday with killing U.S. District Court Chief Judge John Roll, 63, and Gabe Zimmerman, 30, a Giffords staff member, and with attempting to murder Giffords and two other members of her staff, Pamela Simon and Ron Barber.

Giffords was shot in the head and is in critical condition. Simon and Barber are recovering, doctors said.

Investigators have not found the black bag Loughner had that morning and don't know what was in it, Nanos said.

Sometime that morning Loughner made two trips to Walmart and made some purchases, Nanos said. He declined to specify what Loughner bought.

At 7:30 a.m. Loughner was pulled over by an Arizona Game and Fish Department officer for running a red light about five miles from the Safeway where the shooting took place, said Jim Paxon, a department spokesman.

Loughner ran the light in his 1960s, dark-gray Chevy Nova on a road that leads to Interstate 10, Paxon said.

The officer took Loughner's driver's license and vehicle registration information but found no outstanding warrants on Loughner or his vehicle. Loughner was let go with a verbal warning, Paxon said.

The officer said Loughner was polite and subdued, and that he didn't see a black bag in the car.

Wildlife officers don't usually make traffic stops unless public safety is at risk, such as running a red light, he said.

"What he did on the morning before the shooting, we're just trying to find all that out. Naturally, we want to find every detail we can," Nanos said, adding that Loughner may have made other stops that morning but could not specify what they were.

FBI agents who searched Loughner's home Saturday in the 7700 block of North Soledad Avenue, near North Thornydale and West Magee roads, after the shooting found a safe containing an envelope with the name "Giffords" and with the words "I planned ahead" and "My assassination," along with what appears to be Loughner's signature, according to court documents filed Sunday.

The writings also included "die bitch," and "(expletive deleted) you pigs," sheriff's Deputy Jason Ogan said.

Reports from the Sheriff's Department released Wednesday show Loughner had contact with deputies in the past on these dates:

• Sept. 23, 2004: Deputies went to Mountain View High School after Loughner reported that another student had poked him with a needle. Loughner told deputies that he was in the cafeteria when another student walked up to him and poked him with something sharp. Loughner then said he got dizzy, became pale and had to be helped to the nurse's office.

Loughner and his parents did not press charges against the student but requested the student get tested for HIV, the report said.

• May 12, 2006: Deputies were contacted by Mountain View High because Loughner was "extremely intoxicated" and had to be taken to the emergency room. Deputies talked to Loughner at Northwest Medical Center, and he said he drank vodka he had stolen from his father's liquor cabinet because "he was very upset as his father yelled at him." The reporting deputy wrote that Loughner's eyes were very red and he was crying.

• Sept. 9, 2007: Deputies received a call about a suspicious van in a street near Loughner's house. Deputies saw a van in the neighborhood that matched the license plate. When a deputy pulled the van over, he smelled burned marijuana.

The driver stepped out of the van and was handcuffed by the deputy after he refused to answer questions. Deputies found a marijuana pipe and a burned marijuana joint. Loughner was in the passenger seat. When deputies asked him if they could search him, Loughner said twice that "he had a right to say no." Deputies asked if Loughner had anything on him before putting him in the back of patrol car, and he said he had a marijuana pipe in his front pocket. Loughner was cited for possession of drug paraphernalia.

• Oct. 10, 2008: Loughner called deputies after he searched his name on the Internet and found a picture of himself linked to a MySpace account for a 29-year-old woman with "myspacedotcomescrewupretard" listed as the e-mail contact. Loughner told deputies the MySpace page was probably made by an old school friend. Loughner told deputies he was trying to get a job and was afraid employers would see this account.

The reports detailed five other contacts officers had with Loughner or one of his parents from May 1994 to March 2010. The cases were minor, for such things as vandalism, a stolen license plate tag and reports of a suspicious vehicle.

Wire services contributed to this story.