South Lake Tahoe residents have been on alert for the past week thanks to some intentional food poisoning incidents at food establishments across the city.

This began last week when a man was caught on security footage pouring an unknown substance into the food self-service counter at a local Raley's grocery store before fleeing the scene on foot. Police released the below photo of the man after reviewing the security footage.

Photo: News Observer

While this was the first reported incident of intentional food contamination, South Lake Tahoe police believe that the man caught on footage could be linked to three similar incidents at the same Raley's that began a couple of weeks ago.

The poisonings escalated this past Sunday when a twelve-year-old boy was hospitalized after eating contaminated food at a Baja Fresh restaurant in the area. Employees reported seeing a man putting an unknown substance on the salsa bar in the restaurant the day before, and customers reported a bleach-like odor from the salsa bar that day.

Since then, it's been confirmed that both the Baja Fresh and Raley's self-serve food stations had been contaminated multiple times prior to police getting involved in both locations.

The child has since been treated and released from the hospital, but investigators still haven't been able to identify the substance used in all of the intentional poisonings. Local authorities and the FBI are investigating and analyzing footage and videos from Baja Fresh on top of the footage and photos from Raley's.

This isn't the first time food poisoning has been used as a direct attack on people. In 1984, an Oregon cult used similar tactics at a pizza restaurant's salad bar in attempts to rig a local election by making the public too sick to vote against them. In that attack, 751 people reported becoming ill.

We're hoping that this series of attacks in South Lake Tahoe does not get up to that level.

(UPDATE: A man has been arrested in connection with the food poisonings at Raley's. It's yet unknown if he was responsible for the poisoning at Baja Fresh and what the contaminant was. More updates to come from the Sacramento Bee.)

(UPDATE 2: KCRA news has confirmed that lab test results indicated the contaminant used in both cases was bleach. Harry Dally is now being charged for both poisonings).