Wichita ? The Justice Department on Friday opened an investigation into the killing of Kansas abortion provider George Tiller to see whether the accused gunman had accomplices.

The department will investigate possible federal crimes in connection with Tiller’s slaying at his church on Sunday in Wichita, Kan. State prosecutors have already ruled out seeking the death penalty against the accused gunman, but federal prosecutors did not rule out doing so as they announced their own investigation.

“The Department of Justice will work tirelessly to determine the full involvement of any and all actors in this horrible crime,” said Loretta King, head of the department’s civil rights division.

Anyone who played a role in the killing, she said, will be prosecuted “to the full extent of federal law.”

The department will seek to determine whether the killing violated a 1994 law creating criminal penalties for violent or damaging conduct toward abortion providers and their patients.

Wichita Police Chief Norman Williams said his investigation of the case would continue and run parallel to the federal effort.

Dan Monnat, an attorney for the Tiller family, said he welcomes “any investigation that will assist in determining all persons who encouraged or assisted this horrible act and result in their prosecution.”

Police have charged 51-year-old Scott Roeder with Tiller’s death. After the killing, U.S. Marshals began providing security to some abortion providers and clinics around the country.

Tiller’s funeral is scheduled for today, and U.S. Marshals spokesman Jeff Carter said federal deputies “are committed to ensuring every individual wishing to mourn Doctor Tiller’s passing can do so in a safe and secure environment.”

Roeder is charged with first-degree murder and is being held on $5 million bond at Sedgwick County Jail.