FLAGSTAFF, Ariz. – New FBI statistics show the vast Navajo Nation saw a sharp increase in the murder rate in 2013 and finished the year with 42 homicides, eclipsing major metropolitan areas with less space and far more people, such as Seattle and Boston.

About 180,000 people live on the reservation that spans 27,000 square miles in Arizona, New Mexico and Utah. It’s a place where culture and language thrive but where jobs are scarce, alcoholism is among the greatest social ills and cycles of violence and lack of access to basic necessities can stifle people’s spirits.

When those factors combine, “you’re always going to find higher crime rates,” said McDonald Rominger, head of the FBI’s office in northern Arizona. “There’s a correlation.”

The number of people killed on the Navajo Nation increased from 34 in 2012, representing a per-capita murder rate of 18.8 per 100,000 people – four times the national rate. The FBI has not yet released a national murder rate for 2013.

Not a single day passed in 2013 before the first incident of deadly violence was reported on the Arizona portion of the reservation, a murder-suicide in Sanders along Interstate 40. Three more people were killed on the Arizona portion that January, according to court documents.

A man was stabbed at home in Dilkon after he made an inflammatory comment about a gay couple, according to court records. Another man shot his nephew with a rifle in a Red Valley neighborhood after an argument while they were drinking. A 4-year-old girl died from brain injuries she suffered when her caretaker repeatedly hit her over the head while wearing a boxing glove.

When someone is killed on the reservation, FBI agents work the case with Navajo police and criminal investigators. The FBI has jurisdiction over a limited set of major crimes on reservations when the suspect, victim or both are Native American. Taking a case to federal court doesn’t preclude the tribe from also prosecuting. But the penalties under tribal law for homicides are far less stringent, with a maximum sentence of one year in jail and a $5,000 fine even for the most brutal crimes.

The FBI typically opens between 75 and 100 death investigations on the Navajo Nation each year, Rominger said. They are further classified as resulting from an accident, natural causes, a crime and self-defense, for example.

The crimes are among the roughly 250,000 calls that 280 Navajo police officers respond to each year, Navajo President Ben Shelly said recently. He said the ratio of officers per 10,000 people is far less than half that of similar nonreservation rural areas in the United States.