Manassas, Va. ? Lawyers for sniper suspect John Allen Muhammad have issued subpoenas to police and FBI detectives and to four reporters from The Washington Post, seeking to find the source of law-enforcement leaks to the newspaper.

The Post has broken several stories since sniper suspects Muhammad and Lee Boyd Malvo were captured in late October. In November, the paper cited anonymous law-enforcement sources saying that Malvo had confessed to several of the sniper shootings. Months later, that report was confirmed through court documents.

Then, earlier this month, the Post reported numerous details of Malvo’s confession, again citing anonymous sources, in which Malvo allegedly said some victims were shot in the head to increase shock value.

Peter Greenspun, Muhammad’s lawyer, has said the leaks were a deliberate attempt by police to taint the jury pool by giving potential jurors a negative impression of the sniper suspects.

Meanwhile, a judge on Friday reiterated his threat to allow prosecution of any Fairfax County police officer who leaks information in the cases against the sniper suspects.

But he refused a defense lawyer’s request for an investigation into who is responsible for the leaks.

Two police officers, Fairfax County Homicide Detective June Boyle and FBI Agent Brad Garrett interviewed Malvo when he made his confession.