Amid growing scrutiny of the state’s practice of shipping inmates to the mainland, a state Department of Public Safety team left for Arizona yesterday to investigate the killing of a 23-year-old Hawaii inmate at Saguaro Correctional Center.

Arizona authorities expect to charge a 21-year-old Hawaii inmate in connection with the killing at Saguaro, a private prison in Arizona where nearly 1,900 Hawaii inmates are housed.

Eloy, Ariz., police said Mahinauli Silva strangled his cellmate, Clifford Medina, while the prison was in lockdown on last Tuesday.

The killing is the second of a Hawaii inmate on the mainland this year and is prompting calls for new attention to the out-of-state prison population.

State Sen. Will Espero, chairman of the Senate Public Safety Committee, said the two inmate deaths raise serious questions about the state’s policy of shipping out inmates and will undoubtedly raise the prominence of the discussion in the 2011 legislative session.

"Maybe this could give us a reason to pause," he said, adding that the Hawaii team in Arizona to investigate Medina’s death needs to answer this question: "Is this prison unsafe, and are there some major security breaches?"

Meanwhile, Medina’s family said they are not getting any details on the killing from the state Department of Public Safety and plan to travel to Arizona to look into the death themselves.

"It’s so frustrating," said Loke Medeiros, Medina’s aunt. "No one from Public Safety talks to us."

Medeiros said that Medina had cognitive disabilities and attention deficit disorder and had recently been placed in isolation. As a result, he could call his family only once a month.

"The day of his death was the day he was supposed to call home," said Medeiros, of Puna. "He had told us he was in what they call the hole."

DPS Director Clayton Frank said he had not gotten official word yesterday on Medina’s cause of death and so could not comment on the case. But he did say the DPS team would be working with Eloy police and with prison officials to investigate what happened and evaluate security at the facility.

Some 1,871 male Hawaii inmates are at Saguaro, a 1,897-bed prison owned by Corrections Corp. of America. About 50 more are at a separate CCA prison in Arizona.

The state spends about $61 million a year to house male inmates on the mainland because there is not enough room for them at Hawaii prisons. Last year, allegations by female Hawaii inmates of widespread sexual abuse by guards and employees at a CCA facility in Kentucky prompted the state to pull all 168 of its female inmates from the prison and bring them back to the islands to serve their time.

Silva, the suspect in the killing last week, remains in custody at the Saguaro Correctional Center and is expected to be charged today or tomorrow, said Sgt. Michelle Tarango, of the Eloy Police Department.

Police did not provide information yesterday on a motive in the killing and could not say why the prison was in lockdown.

Tarango said Silva confessed in police custody to strangling his cellmate, then waiting a "short while" before pushing an emergency button to call for guards.

Medina was sent to Arizona about six months ago and was serving time for first-degree assault on a law enforcement officer, two counts of second-degree burglary, second-degree theft and bail jumping. He would have been eligible for parole in 2012.

Silva was serving time for burglary and theft.

Saguaro was also the site of the stabbing death of Bronson Nunuha on Feb. 18. Two Hawaii inmates — Micah Kanahele and Miti Maugaotega Jr.

have been indicted on first-degree murder charges in the case.

Nunuha was the first Hawaii inmate killed in a private prison on the mainland since the state started housing inmates out of state in 1995, though others have been seriously assaulted.

Officials have said Nunuha’s death appeared to be gang-related. There are no indications Medina’s death was linked to gangs.