A Sonoma State University student last seen in Walnut Creek is believed to have been in Santa Rosa on April 24, his family said Wednesday.

James Abriel, 19, a freshman, hasn't been seen since April 21. But a signal from his cell phone was detected in Santa Rosa on April 24, his mother said.

Also, the teenager's debit card was used at a Rohnert Park 7-11 convenience store on April 22, said Evangeline Abriel.

She described her son as an avid hiker, a successful student with a 4.0 GPA and an accomplished musician who belongs to musical groups including the string orchestra at SSU.

Apparently despondent after the breakup of a relationship, Abriel left suicide notes at his SSU residence hall and in Walnut Creek. A state be-on-the-lookout alert was issued by Walnut Creek police for Abriel, who may have with him a 40 caliber Sig Sauer handgun that is missing from his Walnut Creek home.

"Please continue to search for him and let us know if you think of places he could be," his family said in a statement.

Abriel is 6-foot-1, weighs 180 pounds and had dark blond hair, police said. He may be driving a 1999 four-door white Toyota Camry, with a California license plate, 4GYG766.

Anyone with information is asked to call 911 or the Walnut Creek Police Department, (925) 935-6400, case number 11-13034.