Santa Ana, California (CNN) -- A California judge ordered Wednesday that two Fullerton police officers stand trial in the beating death last year of Kelly Thomas, a homeless man with a mental illness.
Officer Manuel Ramos is charged with second-degree murder and involuntary manslaughter, and Cpl. Jay Patrick Cicinelli is charged with involuntary manslaughter and felony use of excessive force.
Orange County Superior Court Judge Walter Schwarm scheduled the next hearing in the case on May 22.
Schwarm's ruling came after a three-day preliminary hearing that ended Wednesday.
Orange County District Attorney Tony Rackauckas, who's prosecuting the case, told reporters that he expected defense attorneys to challenge Wednesday's ruling in a motion and possibly an appeal.
Rackauckas said the case "was a terrible incident, and we're going to proceed forward and get justice."
"This is a hard thing to file, a case of this nature against police officers, because we have tremendous law enforcement in Orange County," Rackauckas told reporters. "This kind of incident is very damaging to the community -- to everybody, the police, the community -- because it erodes that trust.
"It brings down the image of the entire community," the county's elected prosecutor said.
Ron Thomas, the father of Kelly Thomas, told reporters after the ruling that the Fullerton Police Department "is full of good officers."
"It's just this band of criminals, these hoodlums," Ron Thomas added.
Ron Thomas noted he and others in his family have worked in law enforcement for "generations."
He said his son would have "never thought a police officer would beat him to death."
The three-day hearing included attorneys repeating a profanity that Ramos uttered to Kelly Thomas, who had schizophrenia, before a total of six police officers were involved in subduing and beating him.
Rackauckas said he repeated the obscenity several times in court to show how Ramos' conduct was "a very far departure from professional and reasonable police" practices.
Kelly Thomas was shirtless and with a backpack when Ramos first approached him in response to a police call that a transient male fitting that description at the Fullerton bus depot was "trying door handles," attorneys for both sides said. The incident evolved into a police inquiry into "a minor property crime" possibly involving receiving stolen property, Rackauckas told the court.
During testimony earlier Wednesday, Orange County coroner's pathologist Dr. Aruna Singhania continuing answering questions for a second day from attorneys for Ramos and Cicinelli about the autopsy she performed on Thomas, 37, after the July incident.
Ramos and Cicinelli have pleaded not guilty to the charges.
Later, in presenting arguments before the court ruling was issued, Rackauckas told the judge that there's sufficient evidence to put the two officers on trial.
"It's a very bad day in Orange County when we have to charge two police officers with these kinds of terrible crimes," the county's elected prosecutor told the judge. "They're sworn to uphold the law, and they're entrusted with the authority given to them by the state of California."
Defense attorneys objected when Rackauckas continued his comments and started speaking of the "awesome power" with which police officers are entrusted.
"This is not a press conference," said attorney Michael Schwartz, representing defendant Cicinelli.
The prosecutor discontinued that line of argument and began addressing other topics after the judge told him: "The court does understand the powers that police officers have, and the level of trust that society places in police officers."
John Barnett, the attorney for Ramos, argued that prosecutors didn't provide sufficient evidence to order his client to stand trial.
On Tuesday, Singhania provided the court with nearly two dozen autopsy photos, prompting Thomas' mother and father to leave the courtroom, as they did on Monday when a videotape of the beating was played. The 16 minutes of video came from a surveillance camera at a downtown Fullerton bus depot where the incident occurred.
Singhania testified Tuesday that based on her autopsy, medical records and the videotape, she determined mechanical chest compressions with blunt cranial injuries caused Thomas' death.
Singhania also testified that Thomas suffered a complete hemorrhaging of his left eye.
Thomas was beaten by police during the July 5, 2011, incident and died five days later, prosecutors say. The FBI is investigating civil rights violations in the case, as well.
Rackauckas has said that Thomas suffered brain injuries, facial fractures, rib fractures and extensive bruising and abrasions. The county coroner listed his manner of death as a homicide and said he died because he was unable to breathe after having his chest compressed.
Ramos, 37, a 10-year veteran of the police department, would face a maximum sentence of 15 years to life if convicted, authorities said. Cicinelli, 39, a 12-year Fullerton police veteran, would face a maximum of four years in prison if convicted.
CNN's Stan Wilson contributed to this report.