CONCORD, N.H. (AP) -While the search goes on for their bodies, Sarah and Philip Gehring’s mother has begun preparing for a memorial service.

Teresa Knight retrieved her children’s personal belongings from their father’s condominium last week.

Their father, Manuel Gehring, admitted he shot his 14-year-old daughter, Sarah, and 11-year-old son, Philip, after a July 4 fireworks display in New Hampshire, and buried them somewhere off Interstate 80 – he thought it was Ohio.

He pleaded not guilty to two counts of first-degree murder and is being held without bail in Merrimack County jail.

Knight petitioned the court for permission to enter his home to collect the personal items so they’ll be available for a memorial service. No date has been set for the service.

The children’s grandfather, Robert Gehring, and the Merrimack County Sheriff’s Department helped Knight collect the items, said her attorney, David Phillips of Manchester.

Robert Gehring, who lives in Reston, Va., offered to help, said Phillips.

Knight, 44, of Hillsboro, has not spoken publicly about the case. Phillips said she initially planned to have a memorial service this week, but the plans were delayed.

The petition said Manuel Gehring’s condominium is not a crime scene and the children’s belongings are not evidence. Authorities continue to search for the children’s bodies.

Gehring spent a week in the Midwest with arresting officers, presumably helping them to try to find the children, before he was returned here to face murder charges.