Mark Hacking, who was the prime suspect from the day his wife, Lori, disappeared, was arrested Monday for investigation of aggravated murder.

Almost from the beginning, the evidence "strongly indicated Lori was the victim of a homicide and Mark was the individual responsible. We focused on him the very first day," said Salt Lake Police Chief Rick Dinse, in a press conference at police headquarters Monday.

A July 19 preliminary police report, obtained by the Deseret Morning News, backs up the chief's statement.

Officers, according to the report, went to the apartment to maintain security just hours after Lori was reported missing.

Just as one officer arrived, he noticed Mark Hacking walking out "holding two cell phones, a small tin container, a blue cloth and a lighter," according to the police report.

The officer asked Mark to stay with him until detectives arrived. While they were waiting, one of Mark's brothers showed up.

"Mark's brother approached the apartment and asked Mark what was happening. Mark said, 'Apparently they're nervous that I bought a new mattress.' Mark then said, 'I just need to get away,' " according to the police report.

The report also outlined how investigators were finding holes in Mark Hacking's story very early in the investigation.

At 9 p.m. July 19, one of Mark's relatives told police that Lori never ran alone and that 5 a.m. was "an unusual time for Lori to be running," the police report states.

"This statement was contrary to the initial information I received (from Mark Hacking)," the officer stated in the police report.

Douglas Hacking, Mark's father, told police that he had received a phone call about 10 a.m. on July 19 from Mark, who said he was worried that Lori had not returned from her morning jog.

"He told Douglas that he woke up" and noticed "her clothes she laid out to wear for the day were still there and her lunch was still in the fridge. So he drove to Memory Grove and found Lori's car. He searched around but didn't find her," according to the police report.

Earlier in the day, however, Mark Hacking had told another officer that after he woke up and noticed his wife wasn't home, "he just assumed his wife had come home and decided to let him sleep and drove herself to work."

Investigators later learned that Hacking was actually in the process of trying to buy a mattress about 10 a.m. from two different stores. He didn't leave the parking lot of Bradley Sleep Etc. 2255 S. 300 West, until 10:30 a.m. to 10:35 a.m.

The police report also detailed some of the evidence seized on July 19. That evidence included papers, two T-shirts that said "Big Rock" and "West Seattle Acid Party," a hat, orange twine, pillow, pillow cases, bedding packages, men's athletic shoes size 11, a blue and white plaid shirt and a pair of men's denim jeans.