Prosecutors said Anthony Garcia targeted former co-workers and their loved ones after he was fired from a residency program at Creighton University

Disgraced Doctor Convicted of Killing Four in Years-Long Revenge Plot After Being Fired

Anthony Garcia, a former medical resident, became a convicted serial killer Wednesday afternoon as jurors returned guilty verdicts on his four first-degree murder counts, PEOPLE confirms.

Garcia, 42, faces either life imprisonment or the death penalty, court officials tell PEOPLE.

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His sentence will depend on the outcome of a Nov. 8 ballot question being put before the Nebraska voters that could abolish the state’s death penalty.

It’s the ending to what prosecutors have described a years-long series of revenge killings that started with Garcia’s firing from a residency program at Nebraska’s Creighton University School of Medicine.

In 2008, Garcia fatally stabbed 11-year-old Thomas Hunter, the son of Creighton faculty member Dr. William Hunter. Also killed in the family’s Omaha, Nebraska, home was the family’s housekeeper, 57-year-old Shirlee Sherman, who was reportedly stabbed more than 15 times..

For years, the case was bone cold, with no suspects and few leads to investigate.

But in 2013, another Creighton staffer, pathology doctor Roger Brumback, was found slain in his Omaha residence, along with his wife, Mary. Prosecutors say Garcia shot and stabbed Roger before stabbing Mary.

Forensic investigators were able to link evidence recovered from the Brumback killings to the Hunter home homicides five years earlier.

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According to prosecutors, all of the evidence pointed squarely at Garcia. The district attorney told jurors the murders were revenge killings — Hunter and Brumback dismissed Garcia from Creighton’s residency program in 2001 — court officials tell PEOPLE.

In subsequent years, Garcia had trouble landing positions with other medical schools and blamed the two doctors for informing them of the firing, prosecutors said. They said Garcia also couldn’t secure medical licenses in other states — something he faulted the doctors for, too.

Prosecutors also said Garcia couldn’t secure medical licenses in other states — something he also faulted the doctors for, court officials confirm.

A probe into Garcia’s cell phone records and credit card transactions proved he was in the Omaha area the night the Brumbacks were murdered, according to court officials. Internet search results also showed Garcia had looked up the couple’s home address.

Police also discovered several incriminating things at Garcia’s Indiana home, according to the Omaha World-Herald, including odd notes to himself (such as to remember to wear Band-Aids on his fingertips and park away from the home), a plan to impersonate another Anthony Garcia and an escape plan by boat.

But Garcia’s lawyer told jurors the state had no direct evidence linking his client to the killings, court officials say. The defense argued, for example, that the Internet searches were planted.

Two months after the Brumbacks’ bodies were found in 2013, Garcia was arrested for their slayings. Three years later, he was convicted.

As the verdicts were read out, the victims’ families — and Garcia’s mother — cried, according to the World-Herald, which described his victims as “four of society’s most innocent.”

One relative told the paper, “What I can’t get over is how could you do that to a little boy? How could you do that to Shirlee, a grandmother who cared for everyone and wouldn’t hurt anybody? To [Roger Brumback] as he just answers the door? And Mary Brumback, the hell she went through as she fought him off?

“He didn’t just kill them. It was torture.”

Attempts to reach Garcia’s attorney about a possible appeal were unsuccessful Thursday. He told the World-Herald the real killer was “possibly” still loose.