An Arizona border sheriff says two suspects may already be in custody after the killing of a U.S. Border Patrol agent along the Mexican border early Tuesday morning. The agent was identified by the Border Patrol Tucson Sector office as Nicholas Ivie, 30.

U.S. Border Patrol Agent Nicholas Ivie (Photo courtesy of U.S. Border Patrol)

The flag at the U.S. Border Patrol checkpoint in Tombstone, Ariz. was at half mast Tuesday morning. (Photo by Michel Marizco - KJZZ)

Jeff Self, the Customs and Border Protection’s joint field commander, was visibly choked up as he read a prepared statement Tuesday.

“Many of the CBP family received this call at 2 a.m. this morning. It’s been a long day for us. But it’s been longer for no one more than a wife whose husband is not coming home," Self said.

Ivie was also a father to two children.

Acting Cochise County Sheriff Rod Rothrock tells KJZZ News two suspects may have already been arrested and in custody in Mexico. He said he does not know who made the arrest, U.S. agents or Mexican agents.

"It’s my understanding that Border Patrol air assets spotted the suspects in Mexico and the suspects were subsequently apprehended but I don’t know the specifics of how that all came about,” Rothrock said.

Authorities say the victim was part of a horseback patrol working in Cochise County. A second agent was shot and wounded is undergoing surgery. A third agent was unharmed.

The shooting occurred about 10 miles east of Bisbee, Ariz. It’s not far from the border. This area of Cochise County has long been recognized as a border region rife with drug smuggling even as the number of illegal immigrants trying to cross through here has dropped in recent years.

The agents worked out of the Naco Border Patrol station which was only recently named for another slain agent, Brian Terry.

Michel Marizco and the Associated Press contributed to this story.

Updated on 10/2/2012 at 10:20 p.m.