ABC News reports that the parents of an alleged serial killer in Tampa, Florida have been ordered by a judge to appear in court after refusing to speak to police during the investigation. Judge Margaret Taylor is calling Howell Donaldson Jr. and Rosita Donaldson to court to answer why they should not be held in contempt for refusing to cooperate with investigators.

Howell Donaldson III, 24, has been charged with four first-degree murder charges. All murders occurred in the Seminole Heights neighborhood in Tampa.

Investigators served the parents with a subpoena to provide testimony about their son, but still willfully refused. Interestingly, the state does not allow parent-child privilege in criminal matters, which means that legally they must answer investigators’ questions.

The couple was subpoenaed to talk to law enforcement on Monday this week, but refused to answer any questions regarding their son and the murders, according to court documents. Their defense attorney claims they have received death threats since Donaldson’s arrest. He also told the press that his clients had been advised about the consequences of their actions.

Donaldson worked at McDonald’s and his manager alerted authorities after finding a gun in a food bag. He was subsequently arrested and the gun was matched to the shootings that took place between Oct. 9 and Nov. 14.

Victims of the shootings are listed as Benjamin Mitchell, 22; Monica Hoffa, 32; Anthony Naiboa, 20; and Robert Felton, 60. Felton was shot on Nov. 14; Naiboa was shot Oct. 19; Hoffa was found Oct. 13 and Mitchell was shot and killed Oct. 9.

There is no known connection between the suspect and victims, and no known motive. Authorities are not searching for additional suspects. Donaldson has not entered a plea to the charges, and is being held without bond.

*Photo credit Hillsborough County Sheriff’s Office