PHOENIX - The Maricopa County Attorney's Office updated its official policy to say prosecutors must review available video evidence before pressing charges in felony cases.

"When we have video evidence to corroborate a crime and/or to serve as the basis for identification, we have to do our due diligence," Maricopa County Attorney Allister Adel told KTAR News 92.3 FM on Thursday.

The policy, which went into effect last month, covers body-worn camera, surveillance and cellphone footage in police possession.

Adel said the update came out of a department-wide policy review and wasn't a reaction to a judge in June throwing out cases in which her office filed gang-related charges against 15 people arrested at a Black Lives Matter protest in Phoenix last year.

"This is something that we have been looking at for a while now, and over the evolution of forming a policy and then going through our committees and making sure that it was written in an appropriate manner and that we distributed it out to our staff, those things take a little bit of time," she said.

She did say, however, that the dismissed cases are a "perfect example of why we wanted to put in writing a policy such as this rather than it just being a verbal suggestion."

The video requirement includes exceptions for cases where other strong evidence exists and charges need to be filed to ensure that a suspect can be held in custody.

"We are trying to make sure that, first and foremost, that we are adhering to our ethical duty as prosecutors and as lawyers in this community to protect the community but also the rights of the accused," Adel said.

KTAR News 92.3 FM’s Taylor Tasler contributed to this report.