Walter Moody was convicted of killing a judge in 1989

An 83-year-old man has become the oldest inmate to be put to death since capital punishment was reinstated in the US in the 1970s.

Walter Moody was convicted of killing judge Robert Vance after sending him a mail bomb in 1989.

He was pronounced dead at 8.42pm local time on Thursday, following an injection at the Alabama prison at Atmore.

He gave no final statement and did not respond when an official asked if he had any last words.

At his 1996 trial, prosecutors described Moody as a meticulous coward who committed murder by mail because of his obsession with getting revenge on the legal system - and then committed more package bombings to make it look like the Ku Klux Klan was behind the judge's murder.

His lawyers didn't raise his age in legal filings, but they unsuccessfully argued in a clemency petition to Alabama's governor that his age and health would complicate the lethal injection procedure.