Authorities arrested two more suspects Saturday in the slayings of three college students who were shot execution-style in a schoolyard, bringing the total number of arrests in the case to five.

The two additional suspects were found in suburban Washington, authorities said.

Rodolfo Godinez, a 24-year-old Nicaraguan immigrant, was arrested in an Oxon Hill, Md., rooming house just north of the I-495 Beltway at about 1 a.m., said John Cuff, an investigator with the U.S. Marshals Service.

An unidentified 16-year-old, believed to be Godinez's half brother, was arrested in Woodbridge, Va., about 45 minutes later. Both were awaiting extradition to New Jersey, Deputy U.S. Marshal Bill Sorukas said.

Authorities were still searching for an additional suspect.

The suspects were wanted in connection with the Aug. 4 slayings in which the victims were forced to kneel in front of a wall behind an elementary school and shot in the back of the head.

Authorities have said robbery appeared to be the motive.

Killed in the attack were Terrance Aeriel, 18; Dashon Harvey, 20, and Iofemi Hightower, 20. Aeriel's sister, Natasha, was shot in the head but survived and has helped police in the investigation.

Shalga Hightower, Iofemi Hightower's mother, said Saturday's arrests gave her peace. "My child can rest now," she said.

The search team, which included the FBI's Fugitive Task Force, staked out the address in Maryland where Godinez was staying after receiving a tip that he was planning to flee to Texas and then to Mexico, according to James Plousis, a U.S. marshal who is responsible for New Jersey.

The tip came from a confidential informant working with federal law enforcement, Cuff said.

Nearly 10 other people, Sorukas said, were arrested for immigration violations in the operation.

In Virginia, Prince William County Police said three others were arrested at the Woodbridge address where the 16-year-old was found. They were arrested on charges of immigration violations and obstruction of justice.

Previous arrests in the case include Jose Carranza, a 28-year-old illegal immigrant from Peru, and two juveniles.