Celina Police Chief John Cullison said Friday he has sent letters to four law firms representing plaintiffs in the civil lawsuits over a recent Celina ISD sexual abuse scandal, a case in which former coach and teacher Caleb Elliott is accused of secretly recording boys in a school locker room, demanding the firms turn over any evidence or witnesses they claim to have to police.

"I want to be very clear that if anyone is going to allege that they have evidence and witnesses related to a criminal case involving children in our community, they have a duty to present that information to law enforcement," Chief Cullison wrote in a statement posted to Facebook.

"As I said at our press conference, when new information emerges in this case, we will review the evidence and file charges on behalf of these victims. I'm backing up my remarks, and I expect these attorneys to do the same," the statement said.

Cullison specifically mentioned a news conference that took place on Wednesday, in which Mitch Little, an attorney and state representative, said his law firm had uncovered more evidence that accusations against Caleb Elliott were mishandled. Elliott, a former teacher and coach, and the son of Celina High School football coach Bill Elliott, faces numerous state and federal charges for allegedly filming boys while they were changing in a school locker room.

In Wednesday's news conference, Little said he had information about an incident in which a fellow coach confronted Caleb Elliott about his behavior long before the scandal came to light, and that there were multiple witnesses.

"There are other persons who were aware of Caleb Elliott's attempts to record and photograph these children in the locker room, and, this is obviously extremely disturbing to us," Little said Wednesday.

Little also criticized Celina PD for saying last month that its investigation had concluded based on the evidence it had. 

"It is now apparent, to me at least, that Celina Police Department has stopped their investigation where they wanted to and not necessarily where the evidence would lead them," Little said Wednesday.

At the time of the police department's announcement, Cullison said they would reopen the investigation if new evidence came to light, which they did when Elliott was hit with additional charges on Nov. 26.

Cullison's Friday statement also mentioned a November news release from the Herz Law Firm that claimed Celina ISD was aware of a relationship between Elliott and a student and a previous recording incident in the middle school locker room. The Herz Law Firm is representing plaintiffs in a civil lawsuit that is separate from the suit involving Mitch Little's firm.

When asked for comment on Cullison's statement Friday afternoon, attorney Paul Herz said,"I have already said in my press release what I will stick with—Celina PD has washed their hands of this case and is sitting back. They refused to look into ISD internal business and the teacher-student relationship—they gave up investigating when the former student would not speak to them. We will cooperate with law enforcement as discovery proceeds, which has not even begun in this case. The question is what they will do without us leading the way for them? We are not hiding anything, we are just beginning the process of uncovering things they did not bother to go looking for."

CBS News Texas has also reached out to Little for comment, and requested copies of the letters Cullison sent.