The 2nd US Circuit Court of Appeals in Manhattan issued its ruling today.
It says that Adis Medunjanin was properly convicted of conspiracy to use weapons of mass destruction and other terrorism charges.
Authorities say Medunjanin, who's originally from Bosnia, had hatched the al-Qaida-sanctioned scheme with two former high school classmates.
The appeals court rejects Medunjanin's claims that some of his statements to authorities were obtained without proper authorization. The 2nd Circuit says he was apprised of his rights repeatedly.