MIAMI, Florida (CNN) -- Federal prosecutors on Wednesday filed murder charges against two men suspected in the deaths of a charter boat crew, authorities said.
The Joe Cool charter boat was found abandoned last month in the Florida Straits.
Kirby Archer, 34, and Guillermo Zarabozo, 19, are scheduled to appear in court Thursday afternoon.
The men are being held without bail on suspicion of killing the four-member crew of the Joe Cool fishing boat last month.
"Four individuals were killed in this case," Alex Acosta, U.S. attorney for the Southern District of Florida, told reporters Wednesday in announcing the charges. "Four families have been torn apart." Watch what led to the charges »
Archer and Zarabozo paid $4,000 in cash for a one-way trip to the Bahamas on the pleasure boat.
The U.S. Coast Guard found the abandoned vessel about 160 miles south of the island of Bimini on September 23. It was unmanned, and its contents were in disarray. Zarabozo and Archer were found a few hours later on a life raft 10 miles from the boat.
Missing are the boat's captain, Jake Branam; his wife, Kelly; and crew members Scott Gamble and Samuel Kairy.
Zarabozo reportedly told a Coast Guard agent that three armed Cuban men hijacked the boat as it headed toward Bimini.
Zarabozo, a licensed security guard, said the hijackers shot the crew members and forced him to throw their bodies overboard.
But, according to court documents filed in the case, Zarabozo and Archer gave inconsistent stories during interviews with authorities regarding what occurred.
Statements given by the pair were not consistent with physical evidence, according to an affidavit supporting the murder charges.
Zarabozo, for instance, told federal authorities he did not own a gun, but an investigation showed he had bought a lock box for a gun he kept at his home. That lock box contained various documents, including a receipt for a February 2007 purchase of a Glock 9 mm magazine and four boxes of bullets.
"Little of the defendants' story rings true," Acosta said.
At a bond hearing last week, the Coast Guard agent said two bullet casings and suspected blood were discovered inside the Joe Cool's cabin. A third bullet casing was found outside the cabin, he said. All three casings were 9 mm.
A fourth 9 mm casing was found on the boat later by family members, who turned it over to the FBI, a relative said.
"Now you have four casings and four people [presumed] dead," said Jeffrey Branam, the uncle of the boat's captain.
Archer is charged with unlawful flight on an Arkansas warrant, accused of stealing more than $90,000 in cash from a Wal-Mart where he once worked.
Last week, a judge said he believes circumstantial evidence shows four homicides took place.
"Your theory is [Archer and Zarabozo] killed the four?" the judge asked the assistant U.S. attorney at the bond hearing. "Yes, your honor," the prosecutor replied.
The Coast Guard spent five days searching for the crew before giving up.
Acosta said it is unlikely their bodies will ever be found. Jake Branam and his wife leave behind two small children, he said.
"It's difficult," Jeffrey Branam said last week. "Some relatives still think the four are alive and are still searching for them."
He said the name of the boat has been removed from the stern, and the name will be retired from the charter fishing business. The boat probably will be retired, too.
Referring to Archer and Zarabozo, Branam said: "I'd like to use them as shark bait." E-mail to a friend