SAN DIEGO - A 21-year-old jiu-jitsu enthusiast from Guam accused of fatally stabbing his Navy Ensign brother during a drunken fight in the victim's Mission Valley apartment pleaded not guilty Tuesday to a charge of murder and the use of a knife.

Zachary Jay Castro Tenorio was ordered held on $1.5 million bail in the death of 25-year-old Navy Ensign Jonathan "Jake" Tenorio. The defendant faces 26 years to life in prison if convicted, Deputy District Attorney Roy Lai said.

Lai said the defendant plunged a 6-inch kitchen knife into the chest of his older brother during the alcohol-fueled struggle on Jan. 27 but did not call for help immediately. Police and paramedics found Jonathan Tenorio dead in a bloody bedroom sometime after 6:30 a.m.

"It's incredibly tragic from all points of view," the prosecutor said outside court.

Zachary Tenorio was arrested after being questioned by homicide detectives. Lai did not disclose a motive for the slaying.

Jonathan Tenorio, a native of Guam, graduated from the U.S. Naval Academy in Annapolis, Md., in May and was assigned to the San Diego-based guided-missile cruiser USS Bunker Hill, Navy public-affairs Lt. Rick Chernitzer said.

The brothers' father, Joe Tenorio, told Pacific News Center in Guam that Zachary Tenorio had traveled to San Diego to compete in a weekend jiu-jitsu tournament.

Last summer, the older brother married Christine Santos, an assistant attorney general in Guam and stepdaughter of Frank Blas Jr., a former senator in the U.S. island territory, the father told PNC.

A readiness conference is set for March 12 and a preliminary hearing for April 11.