Jonathan Guillen, Jr., is believed to be with his father, Jonathan Guillen, Sr.

SAN ANTONIO (December 18, 2012)—An Amber Alert remained in effect Tuesday for 11-month-old Jonathan Guillen, Jr., who was last seen Monday in San Antonio.

He’s believed to be with his father, Jonathan Guillen, Sr., 23.

Guillen was driving a black 2002 Chevy Trailblazer with Texas license 7CZTJ, but authorities said Tuesday the vehicle has been recovered.

Police don’t know what Guillen is driving now.

The missing boy is 2-foot-6, weighs about 25, pounds and has brown hair and hazel eyes.

He was last seen wearing blue jeans and a red hooded sweatshirt.

Jonathan Guilllen, Sr., is 5-foot-8, weighs 185 pounds and has brown hair and brown eyes.

He was last seen wearing a white muscle shirt and black or red shorts.