In December 2007, a woman named Sarah Roberts came forward to sheriff's detectives with some interesting information about a man she had been dating.

Three months prior – Sept. 14, 2007, to be exact – he told her on the phone that he was in the Bay Area and was being chased by police. A friend had been shot, he said, but they couldn't get to a hospital or there'd be trouble.

And later that night, as the boyfriend walked in on her watching the evening news, he became nervous and changed his story about the day's events.

On the news was the gruesome story of Sean Aquitania and his infant son, both killed during a home-invasion robbery in southeast Sacramento County earlier that day.

Four years after that pivotal interview, sheriff's detectives on Thursday arrested their third and final suspect in the case, 28-year-old Christopher Strong.

Strong was the friend accidentally caught in the gunfire that day, detectives allege, suffering a hole just above the knee that acquaintances tended to with alcohol, gauze and masking tape, according to detectives' written request for a warrant for Strong's arrest.

Strong limped for months, but explained it away as a basketball injury, wrote Detective Brian Meux.

Arrested in October were 27-year-old Donald Ortez-Lucero and 34-year-old Richard Noguera, whose girlfriend ultimately sent detectives their way. All three suspects are accused of murder, burglary and attempted robbery.

Thursday's arrest brings to an end an emotional and complicated case that has long haunted local residents, as well as the detectives assigned to it.

"It's certainly the one I've lost the most sleep over," said Meux, a five-year veteran of the homicide team.

What exactly played out at the Country Greens Court home that afternoon is still unclear.

Sean Aquitania, 21, went to the home to visit friends and brought along his 7-month-old son, Sean Jr. At about the same time, detectives say, his friends were being robbed at gunpoint inside the home.

Meux said one of the suspects confronted Aquitania as he pulled up, pistol-whipping him in the head and causing the gun to discharge.

That's when detectives suspect the baby was shot – by accident, not execution-style, as authorities believed early in the case, Meux said.

But detectives suspect nobody knew the baby had been hit. Meux said Aquitania went into the home "under duress" and might have gone back outside at some point, only to discover what had happened to his son. He might have then rushed back inside to fight the suspects, as one of the robbery victims indicated in his statement, Meux said.

During that struggle, the victims – Frederick Dallas Gill and Anthony Palmer – fled, their hands bound with zipties. A neighbor cut them off.

They returned to find the elder Aquitania fatally shot in the living room, and his baby dead in his car seat outside.

When detectives interviewed Roberts two months later, she gave them Noguera's name, as well as the names "Don" and "Chris," according to the arrest warrant affidavit.

It took four years to make arrests, though, in part because detectives were barraged with tips, Meux said.

"This group of suspects was just one of at least a half dozen good leads we had," he said. "There were other people out there that were equally as intriguing or sounded as probable (as suspects)."

As detectives interviewed people from Sacramento to the Bay Area, tapped phones and waited for DNA to be processed, all three suspects came into contact with law enforcement for other reasons.

In February 2008, Ortez-Lucero was stabbed in a bar fight in Oregon, and Strong was with him, according to the affidavit. Two months later, Ortez-Lucero was arrested. DNA collected then would later match with material found under Aquitania's fingernails, the affidavit states.

In December 2009, Sacramento police arrested Noguera on suspicion of domestic violence on his girlfriend. She later told sheriff's detectives that Noguera recently had mentioned being involved in an incident in which he had accidentally shot a baby, according to the affidavit.

"Noguera told her he then had to kill the father," Meux wrote.

The affidavit indicates detectives identified several people who had knowledge of the suspects' alleged involvement, but never came forward, including the mothers of Strong and Ortez-Lucero.

But Meux applauded those who did, including Roberts.

"We're thankful that there are good people out there like them that stepped up … even though it's outside of their comfort level."

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