The Arapahoe County Sheriff’s Office says it has an “open and active investigation” into how rat poison ended up in a to-go food order of a man who bought burritos Sunday from a Taco Bell restaurant in the Denver suburb of Aurora, CBS Colorado’s Brian Maass reports.

“Right now what we’re looking at is if the rat poison was actually put into his food at the restaurant. We don’t know if it was, at this point in time,” Sheriff Deputy John Bartmann told the station, adding that the case is categorized as “criminal attempt homicide.” 

Bartmann and the restaurant manager, Lary Swift, both told CBS Colorado that a male customer came into the restaurant around 1 p.m. Sunday and argued with restaurant workers about his food order.

CBS

Swift said the man was upset that the restaurant’s drink station was not working and “wanted something free.” Swift said the man argued with employees and other restaurant customers. She said the man is a regular patron who’s caused problems before. On one occasion, she said, he threw a taco at an employee.

Swift said he ordered three bean burritos and was given a fourth burrito free.

Bartmann said that at about 7 p.m., the man ate the restaurant food and “became violently ill” and called 911. He was transported to an area hospital.

“That hospital said they had a patient who has possibly consumed rat poison in his food from the same restaurant,” said Bartmann.

Bartmann declined to release the man’s identity but said enough rat poison was found in the burritos that “it would have been very serious to our victim’s health.”

Deputies closed the restaurant on Sunday evening.

Swift said police came back asserting that the eatery had “poisoned somebody.”

“We don’t carry poison in the restaurant,” she said. “We didn’t do anything like that. It didn’t even add up. It’s ridiculous.”

Swift said the restaurant turned over surveillance video to Arapahoe County Sheriff’s Office investigators and the sheriff’s office said it was reviewing the video as well as other evidence it had collected.

CBS Colorado contacted Taco Bell’s corporate communications via email but didn’t immediately receive a response.