Wichita ? A federal grand jury is investigating whether the murder last year of Dr. George Tiller, one of the nation’s few late-term abortion providers, was connected to a broader case involving radical anti-abortion activists, according to a federal law enforcement official familiar with the case.

The official spoke Friday to The Associated Press on condition of anonymity because he was not authorized to publicly discuss the investigation. The official said federal civil rights prosecutors were holding grand jury proceedings in Kansas City, looking into whether a broader case surrounded Tiller’s death.

Tiller was fatally shot in his Wichita church in May 2009 by anti-abortion activist Scott Roeder, who admitted to the shooting and is serving a life prison sentence.

“Yes, there is a grand jury investigation. I can tell you that there are several attorneys from Washington, D.C., looking into this matter and are looking into the broader case than just the actual incident that occurred in Wichita,” the official said.

A spokesman for the U.S. Attorney’s Office in Kansas declined comment Friday.

Roeder, of Kansas City, Mo., said during his trial in January that he believed the killing was justified to save the lives of unborn children.

At least one Justice Department civil rights prosecutor attended Roeder’s trial, along with agents from the FBI. Shortly after Tiller’s death, the Justice Department increased security around women’s health facilities and opened an ongoing investigation.

In recent days, talk of a grand jury in Kansas City began swirling among some anti-abortion activists who have kept in contact with Roeder since he went to prison, including Jennifer McCoy.

“It won’t change things for Scott, and that is what makes me think the problem is the rest of us,” said McCoy, who was sentenced in 1997 to 2 1/2 years in prison for arsons at two Virginia abortion clinics. “They have gone in trying to prove some conspiracy that doesn’t exist.”

McCoy, who said she has not been subpoenaed, now lives in Wichita and befriended Roeder after his arrest in Tiller’s death. She said she learned about the grand jury investigation from Roeder.

Tiller’s clinic in Wichita has been closed since the doctor’s death. The building is for sale.