The vigil at the Crossroad Christian Center was the fourth held in honor of Sierra since she disappeared. Organizers say the gatherings are important to maintain public awareness and keep the focus Sierra.
Friends made more than 500 pink and black ribbons to pass out at the vigil. Pink and black zebra stripe is one of Sierra's favorite things.
"Tonight we wanted to have the ribbon theme where we could just get the public wearing these," said family friend Tonya Miller.
Sierra has only lived in Morgan Hill since October, but there has been an outpouring of support for her in the community.
The 15-year-old was last seen the morning of March 16 before she left home for school. Since then, investigators have found her cell phone and handbag with clothes folded inside.
Yet despite those discoveries, no one has any idea if Sierra ran away or if something bad happened to her.
Friends of the LaMar family who organized Sunday's vigil are remaining optimistic. They are holding out hope that Sierra is out there alive and well.
Pastor Greg Quirke of South Valley Community Church said: "I think that everyone is trying to have the mind set that until something is said, we're going to stay positive and we want to see Sierra come home."