A three-year-long hunt for a suspect in the fatal shootings of two young girls in eastern Oklahoma ended Friday when authorities announced murder charges against a man who claimed he fired at two monsters on a rural road.

Kevin Sweat, 25, who was already in custody in connection with another killing, was charged in the June 2008 deaths of Taylor Placker, 13, and Skyla Whitaker, 11. An affidavit filed Friday at the Okfuskee County Courthouse said Sweat told an investigator he saw "'two monsters' come at him" and fired at them with .40- and .22-caliber handguns.

Prosecutors will seek the death penalty. Sweat also faces a murder charge in the unrelated death of his girlfriend, Ashley Taylor, and the head of the Oklahoma State Bureau of Investigation said her disappearance led them to look at Sweat again in the girls' deaths. Taylor went missing in July after telling her parents she was eloping with Sweat.

"After the death of Ashley Taylor a lot of things started to come together," OSBI director Stan Florence said after a news conference on the courthouse lawn.

Investigators had talked to Sweat before Taylor's July death because he owned a .40-caliber Glock — Glock casings were found near the girls' bodies, but there was no other reason to link him to the crimes, Florence said.

Ballistics tests on five shell casings found at the scene showed they were from the same gun, and matched casings found on Sweat's father's property near Weleetka when investigators began looking at Sweat anew.

Meanwhile, the FBI traced the gun through its various owners, including the Baltimore Police Department. OSBI said it wasn't unusual for police departments to buy newer guns and then trade or sell them back to dealers when they got older.

A gun dealer who had the gun in 2006 and 2007 said he sold it to Sweat. Sweat initially told investigators he sold the gun in 2007, but in a September interview said he fired a Glock at the "monsters."

"Sweat said that on June 8, 2008 during the afternoon, he was driving his black Chevrolet Cavalier car on North 3980 Road in Okfuskee County, Oklahoma," OSBI agent Kurt Titsworth's affidavit says. "Sweat pulled over on the side of the road and saw 'two monsters' come at him. Sweat then panicked. ... Sweat then 'shot the monsters' with the Glock handgun. Sweat then grabbed a '.22 caliber' gun from the glove box and 'shot the monsters' with the .22 caliber gun."

Sweat's attorney in the case involving Taylor's death, Peter Astor of the Oklahoma Indigent Defense System, didn't immediately return a message left Friday afternoon seeking comment.

Sweat pleaded guilty to a misdemeanor drug charge in February 2010 and received a six-month suspended sentence, according to online court records.

He may have tried to sell the Glock at a gun show in Tulsa this March, officials said. A reward of $5,000 reward is being offered for the firearm.

The charges come more than three years after family members discovered the girls along an unpaved road less than a half-mile from Placker's home. They had been headed for Bad Creek Bridge, where they planned to wade through waist-high weeds to the river bank to collect shells and pebbles.

Their deaths were one of a series of tragedies to strike the town of barely 900 people.

Weleetka residents also have been shaken in recent years by a house fire that killed six people; the death of a beloved youth minister in an oil tank explosion; and a fire that tore through several downtown buildings.

At the site of the killings, five miles northeast of Weleetka, cars drove past a makeshift memorial on the side of the road near where the bodies were found. Tattered stuffed animals, including rabbits, bears and a leopard, sat among statues of guardian angels and a large wooden cross bearing the girls' birthdates and day of their deaths.

Tammy Smith, the secretary at the grade school the girls attended, listened in as prosecutors and investigators announced the arrest.

"I just held my daughter in my arms and cried while we listened to the press conference," Smith said. She said she's not sure, though, if the tears she and her 14-year-old daughter shed were out of relief or concern that such a horrible crime could happen again.

Librarian Debbie Wallace said between them, the girls had checked out nearly all of the school's book collection. When she heard Sweat had been charged, she "immediately started bawling."

Wanda Mankin, principal of the Graham School, has marked each day since the girls' grisly murders in 2008. "It's been three years, six months and one day, but who's counting?"

Like many teachers and parents in the small town, she worries there could be more than one culprit.

"There could be someone out there who could be wanting to hurt somebody else," Mankin said.

Florence believes Sweat acted alone — taking advantage of the situation.

"It was a very remote area — not easy to get to," he said. "It wasn't a location that would be typically someone would run by or drive by. It is totally out of the normal flow of traffic."