Obsession unleashed a deadly rage in Darek Nelson and ignited his relentless knifing of a restaurant co-worker who rebuffed his romantic pursuits, according to criminal charges filed Tuesday in southwestern Minnesota.

Squad car video shows Nelson, 24, gripping a hunting knife and standing over 18-year-old Vinessa Lozano's collapsed and bloodied body outside the Montevideo Pizza Ranch on Friday, the criminal complaint read.

Nelson crouches down, looks at the police car and gets in one more thrust with his weapon before he follows the officer's order and drops the knife, the complaint cited the video as showing.

According to the criminal complaint:

Lying in a pool of blood, Lozano gasped for breath as a police sergeant asked who attacked her.

"Darek," she said, bleeding from 30 or so cuts to face, chest, back, under her chin and elsewhere. The knife lay three feet away.

"Darek who?" the sergeant asked.

"Darek Nelson."

Her consciousness faded as Lozano was moved into an ambulance. Less than 45 minutes later, she was dead at Chippewa County-Montevideo Hospital.

In a jailhouse interview, the softspoken Nelson described himself as a loner who spent much of his time in his bedroom playing video games, watching Japanese cartoons and listening to Japanese music.

He described Lozano as "the second-dearest person to me" and acknowledged his feelings toward her were not returned.

Nelson said the situation turned desperate for him when Lozano didn't follow through and visit him at his parent's home. It was that rebuff that inspired thoughts of murder.

On the day of the killing, Nelson said he was miserable and felt Lozano had shunned him. As they both left work that night, Nelson continued, he never talked to her as he walked slightly behind her out of the Pizza Ranch entrance.

He said he first stabbed her in the back.

"What are you doing?" Nelson recalled Lozano saying.

"I knew it was way too late," Nelson told police, "so I kept going."

Another employee briefly interrupted the attack until Nelson swung the knife at him.

Nelson remains jailed in lieu of $750,000 bail on charges of second-degree murder, first-degree manslaughter and two counts of assault. State records show Nelson had no convictions or arrests in his past.

Lozano had an 18-month-old son and was engaged to be married, family said. She graduated from Montevideo High School last year and had started classes at Minnesota West Community and Technical College in Granite Falls. In addition to working at Pizza Ranch, she also had a job as a certified nursing assistant at the Luther Haven nursing home in Montevideo.

Paul Walsh • 612-673-4482