A Stop & Shop security camera shows Marco Riz entering the store on Quaker Lane in Warwick on Sunday. The police say he kidnapped a woman sitting in an SUV in the parking lot, drove to Providence and raped her. Photo provided by Warwick police

Marco Riz had just been fired from his job as a cook at a Texas Roadhouse restaurant on Sunday, a Warwick police captain said, so he walked about a half-mile to the busy Stop & Shop supermarket on Route 2 that afternoon, went inside and changed his shirt.

When he came back out, he saw a Ford SUV idling close by the store, with a 30-year-old woman sitting in the passenger seat. The woman’s mother had just stopped into a nearby store to pick something up, said Warwick police Capt. Michael Babula. She didn’t expect to be more than 10 minutes.

In that moment, the police believe, Riz saw an opportunity. By the time the mother emerged from the store, the SUV was gone — and her daughter was in fear for her life.

Riz, an illegal immigrant from Guatemala, is now in jail for kidnapping, robbery and rape after an intense multi-agency investigation tracked him down Thursday afternoon in Providence’s West End. He’s being detained by the U.S. Immigration and Customs Enforcement as a fugitive alien. ICE spokeswoman Paula Grenier said Riz had been ordered deported from the United States before, but she was unable to answer when the deportation order was issued or why.

Police detectives in Warwick and Providence are calling last Sunday’s attack “horrific” and “atrocious,” and utterly random. Riz and the woman he’s accused of kidnapping, robbing and raping were strangers, their lives connecting only by happenstance. “This poor woman was picked because she was there,” Babula said.

It was a sunny late afternoon, shoppers walking in and out of the store, pushing carriages in the parking lot, seemingly oblivious to the man who opened the door to the idling SUV and jumped inside, brandishing a long kitchen knife at the surprised woman in the passenger seat.

“He was very bold,” Babula said, “and I think from outside the car, nothing got anyone’s attention.”

Riz robbed the woman at knifepoint of her money and credit cards, Babula said. Then he put the SUV in gear and drove away with her.

They headed toward Providence.

Meanwhile, in Warwick, the mother had left the store and realized the SUV was gone. She waited, wondering where her daughter was, and her concern began to grow, Babula said.

Riz drove the woman into Roger Williams Park, where he pulled the SUV off to the side and forced the woman out of the passenger side into the park, according to a police report. He took her into the woods, down by a path, where he sexually assaulted her, according to the report. It was around 6 p.m. and still light out. He became nervous where they were, and moved her to another spot, where he assaulted her again, the report said.

Afterward, he took her back to the SUV and drove to Elmwood Avenue near Roger Williams Avenue, where he took off from the SUV and left the woman behind, the report said.

Back in Warwick, the woman’s worried mother called the police. The officer who responded called the woman’s cell phone, Babula said — reaching her just after the assailant had fled.

Warwick and Providence police joined forces with the state police, the U.S. Marshals, and the investigators of Immigration and Customs Enforcement. “From the first moment, everyone took this with great seriousness,” Babula said. “Everyone took this as what it was, a terrible crime. … This is one of those that sticks in your mind.”

In short order, they had the suspect’s picture from the Stop & Shop surveillance camera, but the victim didn’t know who he was. They needed a name.

On Tuesday evening, the police appealed to the public for help and broadcast the surveillance photo on the news. In less than a half-hour, Warwick police had their first tip on Riz’s identity.

But the Guatemalan man had at least a dozen aliases, said Providence detective Capt. Hugh Clements, and at first the police were searching for him under one of his aliases: Saul Pizzarro-Aviles. When they tracked him down at 183 Linwood Ave. in the city’s West End, Clements said, they matched his fingerprints and learned his real name: Marco Riz.

Riz, 26, is scheduled to be arraigned in Providence District Court on Monday. He faces charges of kidnapping and first-degree robbery from Warwick, and two counts of first-degree sexual assault from Providence. “This really was an atrocious crime,” Clements said.

amilkovi@projo.com