11 month old Jonathan Jose Guillen, Jr. is missing.
Police say he's in grave or immediate danger.
They are searching for Jonathan Guillen, Sr. who's 23 years old and is 5 ft 8 inches tall and weighs 185 pounds and has brown eyes and hair.
He is believed to be driving a 2002 Black Chevy Trailblazer with a license plate of 7C2TJ
If you have seen him or know of his whereabouts, call San Antonio Police at (210) 207-7660
Copyright 2015 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.