TAMPA — Investigators had questions for the parents of Howell Emanuel Donaldson III, the suspect in four Seminole Heights killings.

They wanted to ask Howell Jr. and Rosita Donaldson about their 24-year-old son's background, developmental history, gun possession and state of mind.

But both parents refused to answer Tuesday, defying an investigative subpoena, according to the Hillsborough State Attorney's Office. They revealed only the names, addresses and birth dates of family members before refusing to answer other questions.

"That is a rarity," State Attorney Andrew Warren said at a Wednesday news conference. "Because most people understand that they have a duty to answer questions. And when that duty is explained to them by a judge, they're willing to provide us answers."

Warren's office is asking a judge to consider whether the parents should be held in contempt of court. A hearing is scheduled for 10 a.m. today before County Judge Margaret Taylor.

"Mr. Donaldson's refusal to testify .?.?. despite having received a court-authorized subpoena, constitutes indirect criminal contempt," Assistant State Attorney Jay Pruner wrote in a motion filed Wednesday that names the father.

A similar motion was filed against the mother, along with a transcript of her interview with Assistant State Attorney Scott Harmon.

From the beginning, Andrew Shafii, one of two attorneys who accompanied Rosita Donaldson, told Harmon neither of the parents would testify that day.

Harmon began asking questions to establish a record.

Rosita Donaldson said she and her husband have two other children — a daughter, 28, and another son, 13. The children have several aunts, uncles and cousins. Howell had a good relationship with his two surviving grandparents, she said. The family had frequent gatherings around holidays.

"Thanksgiving everyone was at our house," she said.

Shafii interupted. He told her if she wanted to refuse to talk, she needed to say so. Harmon asked if she would continue.

"No," she said. "With all due respect, I'm not answering any more questions."

Her son, Howell Emanuel Donaldson III, faces four counts of first-degree murder in the deaths of Benjamin Mitchell, Monica Hoffa, Anthony Naiboa and Ronald Felton. The four were shot to death during October and November in southeast Seminole Heights.

"We're not only trying to build a case against the defendant, we're trying to ask the broader question of why — a question that the victims' families and the community deserves to have answered," Warren said.

The younger Donaldson was arrested Nov. 28 after he handed a gun in a food bag to an employee at the Ybor City McDonald's where he worked. The employee called police, and investigators later determined the gun was the same one used in each of the four shootings, an arrest report stated.

Donaldson, who police said acknowledged the gun was his, has been jailed without bail since his arrest.

Ralph Fernandez, the attorney representing the Donaldsons, said the parents were devastated by their son's arrest. Their refusal to answer questions, he said, was intended to avoid further emotional pain.

"I think it's important to safeguard these truly significant family values in this time of tremendous family stress," he said. "In their distressed state, they're asked to testify against their son. .?.?. I'm hoping to avoid further grief."

But Warren said the couple was only being questioned as part of the investigation.

"I'm a father. So I recognize and sympathize with the unenviable situation that they're in," Warren said. "But we have an ethical obligation to exhaust every investigative avenue to make sure we understand what happened in this case."

He was asked if the parents might be fined or jailed for their refusal to comply.

"I don't think it's going to come to that," he said.

The state's court filings note the parents have been granted immunity "by operation of Florida law.'' The documents also state that the couple invoked no legal or constitutional privilege to justify their refusal to answer questions.

State law provides immunity to witnesses who are called to testify in a state attorney's investigation, said Stephen Romine, a Tampa-area defense attorney who is not involved in the Donaldson case. And unlike some states, Florida has no law establishing what is known as "parent-child privilege," which would keep communications between parents and children confidential.

Under the law, witnesses in a state attorney's investigation are given what is known as "use immunity," which means they can't be prosecuted based on their statements.

"Tactically, what it does is it gives (prosecutors) a free look at what the truth is," Romine said. The state can only charge a witness if they develop evidence independent of the testimony, he said.

The events in Donaldson's case appear to parallel those of another high-profile case in which Romine assisted.

In 2004, Jennifer Porter was arrested when she drove off after accidentally striking four children with her car, killing two. In that case, prosecutors tried to force her parents to talk about what they knew regarding the hit-and-run.

But they refused, invoking their Fifth Amendment rights against self-incrimination. Fernandez was their attorney at the time.

Prosecutors told the Porters they could not invoke the Fifth Amendment because they had immunity. At a hearing, a judge warned the couple they could be jailed if they did not cooperate. A few days later, they reluctantly agreed to testify.

Contact Dan Sullivan at dsullivan@tampabay.com or (813) 226-3386. Follow @TimesDan.