Roommates of a Guatemalan man shot and killed last week by an off-duty DeKalb County sheriff's deputy say their friend was a quiet day laborer who arrived in the United States six weeks ago.

Deputy Derrick Yancey told police he shot Marcial Cax-Puluc because the man fatally shot his wife in the deputy's home during an attempted robbery June 9. Yancey had picked up Cax-Puluc at a gas station earlier that day to perform work around the house, according to a police report.

Mary Lou Pickel/AJC (ENLARGE)

Marcial Cax-Puluc was shot in the home of DeKalb Sheriff's Deputy Derrick Yancey in Stone Mountain. Yancey says he shot Cax-Puluc because the day laborer had shot his wife.

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Cax-Puluc's roommates doubt the deputy's version of events.

"We're not going to stop until this gets cleared up," roommate Jose Perez, 29, said. "We know they killed an innocent guy who was just trying to get some money to help his mama in Guatemala," Perez said.

Yancey could not be reached for comment Tuesday. No one answered phone calls to his Stone Mountain home.

Roommates at the Stone Mountain-area apartment complex where Cax-Puluc lived described him as a "timid" teenager who didn't speak much. "He was a quiet kid. He didn't smoke. He didn't drink," Jose Perez said.

"He was just getting used to us," said another roommate Luis Perez, 30.

The men said Cax-Puluc was 18 years old, although police have given his age as 23. The undocumented day laborer came from the town of San Pedro Sacatepequez, Guatemala, they said.

Cax-Puluc's brief time in the United States revolved around walking from the apartment he shared with six other men to a gas station where he waited with other Hispanic day laborers for work. He had not had time to explore the area or have any fun yet, his roommates said.

Police said an autopsy was performed on Cax-Puluc. The DeKalb County Medical Examiner's Office referred questions about the case to DeKalb police, who are investigating the incident. A police spokesman said Tuesday there were no additional details regarding the investigation.