GPG error on ppa apt-get update

I am trying to reinstall Jessie from the Debian Trinity Repo I added: deb http://mirror.ppa.trinitydesktop.org/trinity/trinity-r14.0.0/debian jessie main deb http://mirror.ppa.trinitydesktop.org/trinity/trinity-builddeps-r14.0.0/ debian jessie main to : /etc/apt/sources.list file I ran: # apt-key adv --keyserver keyserver.quickbuild.pearsoncomputing.net --recv-keys F5CFC95C in a root console. I then ran: # apt-get update from the same root console, and after it finished reading everything in the package list, I got this error message TWICE in a row: W: GPG error: http://mirror.ppa.trinitydesktop.org jessie Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 96C95152F5CFC95C The above was exactly what I did 3 days ago and it worked at that time. Is there a problem with the public keys or am I somehow doing something wrong? Keith