Updated

Prosecutors have moved to hold onto their ability to seek the death penalty against two cousins in the deaths of four men found buried on a Philadelphia-area farm, although attorneys have said a deal with one defendant would take capital punishment off the table.

The Bucks County prosecutor's office on Wednesday filed notice of aggravating circumstances in the charges against Sean Kratz and Cosmo DiNardo, both 20, in the slayings last summer. Prosecutors said capital punishment would be justified because there were multiple murders and the slayings were committed during commission of a felony and drug felonies.

Lawyers have said DiNardo acknowledged his part in the slayings and told authorities where to find the body of the fourth victim in exchange for prosecutors agreeing not to seek the death penalty. District Attorney Matt Weintraub termed Wednesday's filing as "covering his bases" in case circumstances change.

"We have to make sure we have the right to proceed in seeking the death penalty in case he reneges on his deal," Weintraub said. "Whether he honors his end of the agreement is up to him."

The new filing comes a day before both defendants are scheduled to appear for formal arraignments on homicide, robbery and conspiracy charges, which is the deadline for filing notice of aggravating circumstances needed to seek the death penalty.

The charges stem from the July shooting deaths of 19-year-old Dean Finocchiaro, 22-year-old Mark Sturgis, 21-year-old Tom Meo and 19-year-old Jimi Taro Patrick, whose bodies were found after a grueling, five-day search in sweltering heat and pelting rain that centered on the farm in Solebury, about 30 miles (48 kilometers) north of Philadelphia.

Authorities said in court documents that DiNardo said he lured the four men to the sprawling farm owned by his parents under the guise of marijuana transactions before killing them there. All four were shot and three were set on fire and placed in an oil drum that was buried. The body of Patrick was found in a separate grave after DiNardo told police where to look, authorities said. Kratz is charged in three of the homicides. His lawyer has vowed a vigorous defense.