A Stockton Police officer investigates the scene after a vehicle involved in a suspected bank robbery was stopped on Wednesday, July 16, 2014, in Stockton, Calif.

This Thursday, July 17, 2014, booking photo provided by the Stockton Police Department shows Jaime Ramos, 19, who was booked on suspicion of homicide, kidnapping, robbery and attempted murder in a Stockton, Calif., bank robbery that led to a high speed chase.

STOCKTON, Calif. - A 19-year-old California man was charged Monday with three counts of murder in the deaths of a hostage and two alleged accomplices, and 22 counts of attempted murder of police officers in a bank robbery and running gun battle.

A judge read a total of 35 felony counts to defendant Jaime Ramos involving the robbery on Wednesday at a Bank of the West in Stockton.

The charges, including kidnapping and robbery, could make Ramos eligible for the death sentence if convicted. He is also charged with being a gang member, carjacking and evading police.

It remained unclear who fired the fatal shots in the robbery-shootout. However, California law allows murder charges to be considered against anyone involved in crimes in which someone is killed.

Deputy District Attorney Robert Himelblau said his office won't decide whether to seek the death penalty until much later in the legal process.

Ramos sat quietly in court holding a copy of the criminal complaint and nodded his head when San Joaquin County Superior Court Judge Franklin Stephenson asked if he understood his rights.

Ramos did not enter a plea and the judge ordered him back to court on Aug. 18. Ramos remains in jail with no bail set.

Deputy Public Defender Jonathan Fattarsi, who represents Ramos, said after the hearing that he had only spoken briefly with his client and did not elaborate.

After the brief hearing, Himelblau said more charges might be filed.

"The investigation continues," Himelblau said. "There might be a fourth person we're interested in. Four people could turn into five."

Police say three armed men entered the Bank of the West branch and took three women, two bank employees and a customer hostage. The pursuit and shootout followed when the robbers fled with the hostages in an SUV owned by one of the employees.

Police said Ramos used 41-year-old Misty Holt-Singh as a human shield. It was unclear when she was shot or by whom, but police found her dead in the SUV at the end of the ordeal.

Two other women were injured and survived after being thrown from the moving vehicle or jumping out.

Authorities identified the two slain bank robbers as 27-year-old Alex Gregory Martinez and 30-year-old Gilbert Renteria Jr.

Investigators have linked Martinez to a robbery on Jan. 31 at the same bank branch through surveillance video, witness statements and comparable circumstances.

Police have recovered a dark Buick sedan seen on video dropping off the suspects in last week's robbery. The car had no license plates and had been abandoned in a neighborhood about a 10-minute drive from the bank. The driver is the subject of an active search, police said.

Relatives have said they believe police acted appropriately by engaging the men in a gunbattle, but they struggle to understand what the men were thinking.

Holt-Singh left behind a husband and two children, 12 and 19.