RICHMOND, Va. (AP) – The state of Virginia is asking a federal court to deny an inmate’s request to halt his upcoming execution.   Attorneys for convicted killer Ricky Gray have asked the U.S. District Court in Richmond to stay his lethal injection set for Jan. 18, citing a risk that he’ll suffer a painful death. They are challenging the state’s plan to use drugs from a secret compounding pharmacy.  The attorney general’s office said in a Friday filing that Gray won’t be “irreparably harmed” by the compounded substances. The filing also says there’s a strong public interest in seeing the punishment carried out.  A hearing on the request to halt the execution is scheduled for Jan. 3.  Gray was convicted of killing a Richmond couple and their young daughters on New Year’s Day 2006.