This is the 9203rd most frequent Russian word.
следственным
The word "следственным" means "investigative" in English.
The word 'следственным' is used here as an adjective modifying 'органам', meaning 'investigative' in the context of authorities.
Следственным органам удалось раскрыть дело.
Investigative authorities managed to solve the case.
In this sentence, 'следственным' modifies 'экспертам', implying their role in investigation processes.
За работу следственным экспертам выразили благодарность.
The investigative experts were thanked for their work.
Here, 'следственным' modifies 'действиям', referring to actions carried out as part of an investigation.