TAMPA » A review of surveillance video from a Walmart store where a Tampa family purchased beef later found to be tainted with LSD revealed no evidence of suspicious activity before the purchase, according to a company spokeswoman.

Management at the Walmart store at 1501 N Dale Mabry Highway worked with police following the incident last week that sickened four people, including two children, to try to pinpoint signs that the store’s meat products had been disturbed.

"From what video we’ve reviewed, we’re unaware of any suspicious activity," Dianna Gee, a Walmart spokeswoman, wrote in an email Monday. "There’s no indication that any other products in the store were tampered (with) or the packaging disturbed in any way."

The lack of any obvious wrongdoing within the store leaves open the question of how the package of beef became contaminated with the hallucinogenic and whether any crime was committed.

A Tampa police investigation remained ongoing Monday. Detectives were receiving assistance with further testing of the store’s meat products from the U.S. Department of Agriculture, said police spokeswoman Laura McElroy.

"It’s definitely outside the scope of what we usually do," McElroy said. "We’ve never had a case like this."

Tampa police were called to investigate after officials at St. Joseph’s Hospital notified them last week about a family of four who suddenly fell ill the night of March 3.

Ronnie Morales, 24, was rushed to the hospital that night by his pregnant girlfriend, Jessica Rosado, 31. But after she got there, Rosado and her two children also started experiencing hallucinations.

Doctors induced labor on Rosado, who was nine months pregnant. They also performed tracheal intubations on Morales and the two children, Elyana Serrano, 7, and Rayna Serrano, who turned 6 on Friday. All four were later discharged from the hospital. The baby boy, described by police as healthy, was also sent home.

The symptoms, authorities found, began after the family consumed a package of thin-cut, bottom round steak they purchased at the Walmart store.

The steak was part of the first dinner the family made since moving into the North Tampa rental home two days earlier.

The family members have not spoken publicly about the incident or answered the door for reporters seeking comment.

Police said they had not been called to respond to any incidents in that home in at least the last year.

Tests on the leftover meat and packaging revealed traces of LSD. In the ensuing investigation, police took the family’s oven for testing as well as the remaining supply of meat from the Walmart store. They also took blood samples from the family members to determine how much of the substance they consumed.

The meat was prepackaged on sealed trays by Cargill, police said, a company whose meat businesses are have headquarters in Wichita, Kan.

A Cargill spokesman said Monday that the company had not been contacted by investigators. Neither the FBI nor the Florida’s Department of Agriculture and Consumer Services are involved.

In a news conference Friday, Tampa police Chief Jane Castor said investigators believe the incident is isolated.