OMAHA, Neb. » An Indiana doctor who was fired from a Nebraska medical school more than a decade ago has been arrested on suspicion of killing four people with ties to the school in two separate attacks five years apart.

Anthony Garcia was a medical resident at Creighton University when he was dismissed in 2001 for unspecified erratic behavior. He now stands accused in the killing of a pathology professor and his wife earlier this year, as well as the 2008 stabbings of another professor’s son and housekeeper in a neighborhood near the home of billionaire Warren Buffett.

Garcia, who lives in Terre Haute, Ind., was arrested by Illinois State Police on Monday during a traffic stop in Union County, in southern Illinois. He was jailed without bond.

The 40-year-old physician is suspected of breaking into the Omaha home of Creighton professor Roger Brumback in May. Investigators believe Garcia fatally shot the professor and stabbed his wife, Mary, to death.

Garcia is also charged in the fatal 2008 stabbings of the son of another pathology professor, William Hunter, and his housekeeper in an affluent Omaha neighborhood, just blocks from Buffet’s home.

Garcia was a medical resident when Brumback and Hunter fired him, but neither police nor Creighton officials have detailed the nature of the behavior that led to his dismissal.

Eleven-year-old Thomas Hunter and the housekeeper, Shirlee Sherman, were probably not the intended targets of the 2008 attack, and investigators believe Garcia acted alone, Omaha Police Chief Todd Schmaderer said.

Detectives had few leads in the first killings. Witnesses reported seeing a well-dressed, olive-skinned man parking a Honda CR-V about a block from the Hunter home and walking up to the door with a case of some type.

Authorities released a police sketch based on witnesses’ recollections, and an award for information climbed to more than $50,000. But police were unable to develop any solid leads, despite an airing of the case on "America’s Most Wanted."

Omaha police spokeswoman Lt. Darci Tierney noted that seven years had passed from the time Garcia was fired until the killings of Thomas and his housekeeper.

"For most people, that’s such a long time in between. It’s probably understandable why his name wouldn’t come up," she said.

Tierney said she didn’t know what broke the case, but the progress came after an FBI task force was created to look into the slayings after the deaths of the Brumbacks.

"That gave us more resources and more eyes on the case, and you just start working it from more angles," Tierney said.

When he was arrested during a traffic stop, Garcia appeared to be intoxicated and was in possession of a .45-caliber handgun, police said. Authorities declined to discuss details of Garcia’s arrest or detention.

Garcia appeared in court today in Jonesboro, Ill., about 120 miles southeast of St. Louis. A judge deferred questions over his extradition to Nebraska until Garcia confers with an attorney headed his way, according to a report by the Southern Illinoisan newspaper in Carbondale.

Allison Motta, a Chicago-area attorney who said she was contacted by Garcia’s family to represent him, declined today to discuss the case with The Associated Press as she was traveling to southern Illinois.

A hearing to address Garcia’s extradition was scheduled for Wednesday.

It was unclear where Garcia finished his medical residency after being fired from Creighton.

Since 2003, Garcia has held medical licenses in California, Illinois and Indiana, but his temporary Indiana license expired in January, according to public records.

Neighbors of the Brumbacks were still digesting the news of Garcia’s arrest.

"It saddens us to think that something like this could happen, and no one saw anything," said Carol Fettin, who lives three houses down from the Brumback home. "We racked our brains, trying to come up with something."

Court records show Garcia filed for bankruptcy in 2005, saying he was more than $81,000 in debt. The only assets he listed were about $1,000 in cash and a 2000 Honda CR-V.

One of the Brumbacks’ three children, Darryl, said the family had no comment about the arrest. A male relative of Sherman’s also declined to speak. The Hunter family didn’t respond to a phone message seeking comment.

Associated Press writers Josh Funk in Omaha, Jim Suhr in St. Louis, Grant Schulte in Lincoln and Charles Wilson in Indianapolis contributed to this report.