PORT ANGELES, Wash. -- The body of a baby boy has been found by investigators combing through 60 tons of trash at a dump site near Tacoma.

Port Angeles Police Chief Terry Gallagher told The Associated Press the body was found about 2:10 p.m. Monday, three days after the investigation began, and six hours into sifting through the trash.

VIDEO: Dead Newborn Baby Found At Puyallup Dump Site

Gallagher said forensic tests are planned, and DNA results to establish the infant's parentage may not be available for weeks.

A 16-year-old girl was arrested Friday on suspicion of first-degree murder after a neighbor in Port Angeles told police she saw a dead baby in a garbage can. The girl's father, 41-year-old Ronald Last Jr., was arrested for investigation of concealing the birth by disposing of the body.

According to court documents filed on Monday, the girl gave birth on Tuesday to a baby boy, drowned him in a toilet and put his body in a trash can.

Court documents prepared by the Clallam County Prosecutor's Office alleged that after the boy's birth, the mother's father looked for a new bathroom rug. The girl told him she had bled on it and that she threw it away.

The father looked for the rug in a garbage can, found the baby's body but was too stunned to remove the body from the trash, according to the documents.

The girl is being held on $500,000 bond. She remains in juvenile detention for investigation of first- or second-degree murder.

Prosecutor Deborah S. Kelly says another hearing is scheduled for Wednesday. She says the girl will be charged as an adult.

The girl's 41-year-old father, Ronald Last Jr., also was arrested and is being held at the county jail on $10,000 bond.

The 60 tons of trash were in two containers that were taken to a site in Graham for shipment to Oregon. The trash was handled by Waste Connections, Inc.

"Our belief was the baby was born alive, but died shortly after the birth," Gallagher told KIRO 7 Eyewitness News.

He said the trash was picked up Wednesday. Chopper 7 video showed investigators at the Graham site, where Washington State Patrol officials could be seen.

Gallagher said a woman came to the police station Friday and said she had seen a baby in a trash can in an alley behind the girl's house, but the can was empty when officers arrived.

Police said they found a gun in the house, along with a metal pipe that was first thought to be a pipe bomb. Gallagher said it was actually a device that can be attached to the bottom of a car for transporting illegal drugs, "a fairly common method," he said.