Convicted cop-killer Mumia Abu-Jamal is seeking to overturn a new Pennsylvania law that allows violent crime victims to sue offenders whose speech continues to cause them "mental anguish."

In a lawsuit filed Monday in federal court in Harrisburg, Abu-Jamal's lawyers said the measure - signed in October - violates the First Amendment rights of prisoners and was specifically targeted to silence him.

"This law is clearly unconstitutional," Bret Grote, legal director of the Pittsburgh-based Abolitionist Law Center told the Philadelphia Inquirer. "The Pennsylvania Legislature and Gov. Corbett wanted to use Mumia Abu-Jamal to score political points and passed a law that can't pass constitutional muster."

The law clears the way for crime victims to sue an offender whose conduct "perpetuates the continuing effect of the crime on the victim." It also gives local district attorneys and the state attorney general grounds to seek an injunction against a prisoner preventing such speech.

Abu-Jamal, who is serving a life sentence for murdering Officer Daniel Faulkner of the Philadelphia Police Department, was joined in his lawsuit Monday by two other Philadelphia-area inmates convicted of murder as well as two nonprofit organizations that have long backed his cause. It names Pennsylvania Attorney General Kathleen Kane and Philadelphia District Attorney Seth Williams as defendants.