The word "said" is the past participle of the verb "say". As is the case with almost all past participles, they can double as adjectives in the form that they are in.
Example: (Legal document)
ABC Knives Incorporated shall not be responsible for any damages that are incurred from improper use of the All-in-one Utility Knife or the Easy-Peel Kitchen Blade. Furthermore, under evidence of improper use, ABC Knives Inc. reserves the right to void any warranty of said products.
In this example, the past participle adjective "said" describes the noun "products".