SAN DIEGO (CNS) - A serviceman suspected of beating a fellow Marine to death at Camp Pendleton Sunday remained hospitalized Tuesday with serious injuries he suffered in a leap from a third-floor balcony at the barracks where the alleged murder occurred.

The suspect, whose name was withheld pending charges, was taken into custody at the northern San Diego County military base about 1 a.m. Sunday, shortly after 19-year-old Lance Cpl. Mario Arias of Canoga Park was found dead in his bed, according to the Naval Criminal Investigative Service.

The alleged assailant was expected to recover, though it was unclear how long it will likely take for his condition to improve to enable the prosecution to proceed in the case, NCIS spokesman Ed Buice said Tuesday afternoon.

Authorities have not offered a motive. It was unclear if the suspect jumped off the barracks in a suicide attempt, of if he was trying to avoid arrest.

Investigators are not seeking any other suspects in the case, according to Buice.

"There's no indication that anybody else was involved," he said.

Arias, who enlisted in the Marine Corps in August 2010, was an air-crew trainee with Marine Light Attack Helicopter Training Squadron 303, Marine Aircraft Group 39, 3rd Marine Aircraft Wing. During his 15 months of military duty, he earned a National Defense Service Medal, USMC officials said.