Jason Cooper is a character who appears the first time in His Thoughts Were Red Thoughts.
Following the death of Bret Stiles, he is the head of the Visualize Church.
When Stiles is arrested (in truth the arrest is part of a plan of his to drive his enemies within the church into the open), Cooper convenes the meeting where they were supposedly going to reaffirm Stiles. Instead, with the exception of Nora Hill, everyone votes for Jason Cooper to take the seat at the head of the table, just as Stiles,Teresa Lisbon and Patrick Jane walk in. After the discovery of the real killer, Hill, Cooper is forced to give up, his "coup" against Bret Stiles being discovered.
Instead of having him punished, Stiles forgives him and he stays his second in command. Cooper later helps Lisbon and Jane on a case, in which Visualize was connected to. Later he was among the people called to the dinner and witnessed as the killer (Holly Preston) showed herself.