Jason Morgan Ritter,(born on February 17, 1980) is an American actor, son of the late actor John Ritter, and actress Nancy Morgan. Ritter is best known for his role as Kevin Girardi in the television series Joan of Arcadia, and Sean Walker in the NBC series The Event. He currently plays the recurring role of Mark Cyr in the NBC television series Parenthood, for which he received an Emmy Award nomination. He stars as Dipper Pines inGravity Falls. He cosplayed as his character during SDCC '13. Ritter has demonstrated his love and appreciation for the show on a number of occasions.