Federal prosecutors have decided against charging companies involved in the September 2006 E. coli outbreak traced to contaminated spinach.

Following the outbreak, which led to the deaths of three people and sickened about 200 others, FBI agents raided two produce processing plants and several farms for evidence of environmental and food-safety violations. The investigation did not find that growers or processors had deliberately skirted the law or were negligent in preventing tainted foods from entering the marketplace, said U.S. Attorney Scott Schools.

Authorities had searched plants in October run by Growers Express LLC in Salinas and Natural Selection Foods LLC in San Juan Bautista, as well as farms in Santa Clara, Monterey and San Benito counties.

The outbreak last August and September caused 205 illnesses in 26 states and killed two elderly women and a toddler. The U.S. Centers for Disease Control and Prevention estimated that about 4,000 people were sickened by the spinach, taking into account that relatively few cases typically are reported.

The companies involved in the spinach E. coli outbreak still face civil litigation.