Cottage Grove woman’s blood was on suspect’s firearm, prosecutors say

A Cottage Grove man pleaded guilty Friday, July 10, in federal court to unlawfully possessing a short-barreled firearm that prosecutors say can be linked to the death of 29-year-old Rozaleena Rasmussen.

Anthony Wesley Tyrrell, 33, awaits trial in Lane County Circuit Court after pleading not guilty to murder in the death of Rasmussen. Testing of the weapon he pleaded guilty to possessing revealed “the victim’s blood DNA,” according to a July 1 filing in federal court.

The document filed by federal prosecutors also provides new details about how Rasmussen died.

After Rasmussen had been reported missing, the Lane County Sheriff’s Office announced in June 2024 her body had been found in the Cottage Grove area and later that Tyrrell was a suspect. 

Portland police arrested Tyrrell in October 2024, but the sheriff’s office has released few other details about the alleged murder.

Federal prosecutors in the court filing said Rasmussen’s body “was found burned with a .410 caliber shot to the back of her skull.”

Negotiations between Tyrrell and prosecutors before Friday’s hearing in U.S. District Court in Eugene involved discussions about the pending murder case. 

U.S. District Judge Mustafa Kasubhai ordered a sentence of three years and five months in prison, which would run concurrently with any sentence imposed following a conviction in the murder case, according to court documents.

Tyrrell’s murder trial is scheduled for Aug. 5 in Lane County Circuit Court. He also faces a charge of abuse of a corpse and, similar to the federal court case, a charge of unlawful possession of a short-barreled firearm. 

Rozaleena “Rozy” Rasmussen “had her whole life ahead of her,” said her sister, Moranda Rasmussen, in a phone interview Monday.

”She was really working on turning her life around, and now she doesn’t get that opportunity,” said Rasmussen, 32.

“The last time I spoke with her, she seemed really positive and upbeat and things were going really well for her,” Rasmussen said.

Federal prosecutors, in a sentencing memorandum, described Tyrrell as a one time suspect in a 2023 Cottage Grove bank robbery in which the suspect was seen “entering and exiting” a red Ford Ranger pickup.

Tyrrell, however, denied robbing the bank after an arrest nearly two months later in which he admitted to driving a red Ford Ranger involved in a hit-and-run collision.

In June 2024, after Rasmussen’s body was found in the woods, Tyrrell was interviewed and, according to federal prosecutors, “admitted to being in a verbal dispute with the murder victim over the purchase of drugs, claiming she had ripped him off.” He denied any physical dispute.

Investigators conducting surveillance July 9, 2024, “saw Tyrrell drive his truck into a camp used by unhoused people.” The court document states investigators obtained a search warrant for the Ford Ranger, finding an Iver Johnson Model Champion .410 gauge shotgun in a duffel bag behind the passenger seat.

“The forensics recovered from the firearm confirm Tyrrell possessed it. The fact that it was in his truck confirms that he was riding around with it,” federal prosecutors wrote in the court document filed July 1 in U.S. District Court in Eugene about the unregistered firearm.

“The murder victim’s blood DNA found on the weapon — along with the same-caliber bullet wound in her head — speaks for itself,” prosecutors said.

A separate court filing by Kimberly-Claire Seymour, an assistant federal public defender  representing Tyrrell, stated his “serious misconduct was facilitated by an uncontrolled addiction to methamphetamine and fentanyl, which built upon a backdrop of extreme and traumatic childhood experiences.”