Editor's Note: This story was originally published on Dec. 6, 2017. It has been updated to correct the story's formatting.

TAMPA -- The parents of the Seminole Heights murder suspect have not fully cooperated with an investigative subpoena, according to a court record released Wednesday.

State Attorney Andrew Warren spoke with media members Wednesday on the prosecution of Howell Donaldson III, who faces four counts of first-degree murder. Benjamin Mitchell, Monica Hoffa, Anthony Naiboa and Ronald Felton were all shot to death in October and November in the southeast Seminole Heights neighborhood.

"The parents do have immunity just like anyone would who has been given an investigative subpoena, so anything they say can't be used against them, which means that a judge will likely to compel them to answer questions that are relevant to the investigation," Warren said. "We have filed a motion for an order to show cause, so that the parents can have the opportunity to explain why they declined to answer questions in front of the judge."

A judge will determine Thursday whether or not Howell Donaldson Jr., the father of the Seminole Heights murder suspect, should be held in contempt of court.

Watch: Click or tap here to watch State Attorney Andrew Warren's Wednesday news conference in its entirety

Related: Click or tap here to read Doanldson Jr.'s motion for order to show cause

Warren spoke Wednesday on the difference between testifying at a trial and an investigative subpoena.

"To be clear, no one's been asked to testify to anything," Warren said. "An investigative subpoena has them come and answer questions in a private environment as part of the investigation."

Related: Was father of Seminole Heights murder suspect in contempt?

The Donaldson's attorney Ralph Fernandez said Wednesday in a separate news conference that the parents would not testify against their son.

"The critical issue is this...Call my office if you feel delighted about ratting on your children," Fernandez said. "Does that excite anyone, that prospect? And if it does, you're not my friend."

According to court filings, Donaldson Jr. was served a subpoena Monday, directing him to a testify before Warren. On Tuesday, he appeared at the state attorney’s office along with Fernandez, but refused to answer questions about his son and the Seminole Heights murders.

In Florida, there is no privileged relationship between a parent and their child. It’s on a case-by-case basis. Only five states recognize that relationship as privileged.

"Simply, it comes down to this; they don't want to testify against their son," Fernandez said. "I mean it's simple as the day is long."

Fernandez said "nothing good" could come about Howell Jr. and Rosita Donaldson answering the state attorney's questions as part of the subpoena.

"I've yet to see a case in which a prosecutor has gone out of their way to help us out in defending a client," Fernandez said.

Watch: Click or tap here to watch Attorney Ralph Fernandez's Wednesday news conference in its entirety

Warren said the state deals with reluctant witnesses "regularly in all sorts of cases."

"We're going to use every avenue at our disposal to obtain the most available evidence that we have to determine what happened to bring prosecution against the defendant," Warren said.

Warren said Wednesday he could not speak on whether or not Donaldson III had a mental illness.

"Mental illness, in my view and in my role as the state attorney, is to evaluate whether someone is competent to stand trial, and in a capital case, to determine whether mental illness played such a role in the commission of the crime that it's a mitigating factor against seeking the death penalty," Warren said.

Warren also reiterated the state could seek the death penalty against Donaldson III.

"If there is a legal basis to seek the death penalty, and it's consistent with the wishes of the victims' families, we intend to seek the death penalty," Warren said.

Related: Hillsborough State Attorney considers death penalty in Seminole Heights murders

Previous: Suspect in Seminole Heights serial killings to stay in jail

More: Sign language interpreter delivered confusion at Seminole Heights news conference

"We want to talk to any witness who may have information about what happened on the nights in question, about the defendant's whereabouts, about the defendant's motivations," Warren said. "So those are the questions that we're asking any witness who we believe may have relevant information in this case."

Howell Donaldson III was arrested on Nov. 28.

Donaldson's parents spoke to the media about their son on Friday.

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Motion for Order to Show Cause Howell Donaldson, Jr by 10News WTSP on Scribd

Notice - Of Hearing Motion for Order to Show Cause Howell Donaldson by 10News WTSP on Scribd

Motion for Order to Show Cause Rosita Donaldson 1 by 10News WTSP on Scribd