Later, as a San Diego police officer, he would downplay his role in saving others' lives as a routine part of his job. "He was very unassuming," his father said.
"He strived to be a detective, and he made it. But his love was being a beat cop."
Mr. Castellini's body was discovered Aug. 26 in his Spring Valley home. The 37-year-old detective was the second San Diego police officer in as many days to commit suicide.
Lesli Lord, 45, died the previous day at her home in Jamul. She was a former SWAT commander, and Mr. Castellini had served on the SWAT team before his promotion to detective.
"I've got to believe it was a momentary lapse of judgment," said San Diego Police Detective Chris Felan, searching for answers to his friend's death.
"Tony was the last person I would expect this would happen to.
"I truly believe that if he could take it back, he would."
Felan described his friend and former beat partner as meticulous and organized, "the consummate partner."
Said Felan: "There was a way about him that would always make you smile.
Even arresting people, getting into a horrendous fight. Afterward, we would look at each other, smile, and say, 'Yeah, we made it. We came through, and we're better for it.' "
Fastidious to a fault about his police uniform, Mr. Castellini once dabbed a barely perceptible food stain with water while dining with colleagues.
Before he was finished dabbing, the stain had mushroomed, virtually covering his chest.
"We had to go and get him another shirt," Felan laughingly recalled.
Mr. Castellini, a San Diego native, grew up in Lemon Grove. He attended Lemon Grove Elementary School and Palm Junior High and graduated from Mount Miguel High.
His father, a painting contractor, wanted his middle son to join the family business. But Anthony had other ideas.
"He said, 'No, Dad, I don't want to be a painter,' " his father recalled.
"He wanted to go to college and pursue a police career."
Mr. Castellini earned a degree in criminal justice at San Diego State University in 1986. As a student he worked as an intern for the San Diego Police Department for six months, specializing in child abuse cases.
During more than a decade in law enforcement, Mr. Castellini was assigned to the Eastern, Western and Northern divisions of the San Diego Police Department.
In 1989, Mr. Castellini received the Medal of Valor from the San Diego Police Department for pulling a suspected car thief from a smoking, overturned car before it burst into flames.
"Tony always had that great smile and exuded tremendous energy," said Tom Hall, a former captain in the Western Division of the San Diego Police Department for whom Mr. Castellini worked.
"He always did his very best to fix a problem and resolve issues. He never took a Band-Aid approach to anything, and that really impressed me."
Capt. Steve Creighton, who promoted Mr. Castellini to detective in May, said, "Tony had lot of turmoil outside the job and the PD was the one place with stability. He was just an overall good cop, and he had a good future here."
Mr. Castellini is survived by his wife, Patricia, of Oceanside; two sons, Michael, 7, and John, 3, both of Oceanside; his parents, Joseph and Norma Castellini of Lemon Grove; a sister, Sandra Garske of Del Cerro; and two brothers, Joe Paul Castellini of San Diego and Rocky Castellini of Lakeside.
Deceased Name: Anthony Castellini, 37 S.D. police detective, Medal of Valor recipient
Long before he began to patrol San Diego streets, Anthony Castellini put a stronghold on fear.
His father, Joe Castellini, saw it when his son competed with a broken hand during a high school wrestling tournament.
"Something wasn't right, because he was using only one arm," the older Castellini recalled. "But I didn't find out until afterward that he had a broken hand."
Despite the disability, young Anthony won each of his matches for Mount Miguel High School that day two decades ago.