FEDERAL WAY - A nursing assistant with no criminal history has been arrested as a suspect in the murder of a Federal Way grandmother whose body was found in the trunk of her car last month, police said.

The suspect, identified as 24-year-old Joseph Njonge, has been booked into King County Jail on suspicion of murder in connection with the death of Jane Carol Britt, 75. She was found strangled to death on March 19.

Njonge, a certified nursing assistant and resident of Kent, worked at the Garden Terrace Alzheimer’s Residential Care Facility at 491 S. 338th in Federal Way. It was the same facility where Britt's husband was a resident and where her car was found.

Britt frequently visited her husband, Frank, at the Garden Terrace facility. She had visited him the day before her body was found in the trunk of her vehicle, a 2002 gold Mercedes Benz, which was parked outside the facility.

Federal Way Police Cmdr. Dan McCall said Friday that the suspect had provided care to the victim's husband, who has Parkinson's disease. "The victim did know him," McCall said.

Njonge was identified through DNA samples found on the victim, Federal Way police said.

He was arrested Thursday without incident while at work at the Garden Terrace facility.

Employees there were stunned to learn that one of their own co-workers was suspected in the killing.

"We're of course very glad that there's progress made in the case, but knowing that it was a staff member of ours is very difficult for us to even comprehend," said Todd Fletcher of Garden Terrace.

Police have said very little about a possible motive for the killing. McCall said Friday that no sexual assault had taken place and that robbery does not appear to be a motive. However, some minor items of the victim's clothing remain missing, he said.

The Federal Way Police Department has worked with the King County Prosecutor’s Office, King County Medical Examiner’s Office and the Washington State Patrol Crime Lab to investigate the killing. As a part of the investigation, forensic and DNA samples were collected for analysis, including fingerprints, hairs and clothing fibers.

On Thursday, the Federal Way Police Department was informed by the crime lab that test results positively matched a DNA sample taken from the victim to the suspect.

Police would say very little about the nature of the DNA sample, except to say that it was not from a sexual assault. However, McCall said "it was not a random or casual sample."

Federal Way police said Njonge worked as a certified nursing assistant at the Garden Terrace Facility.

He has no criminal or police record, except for a couple of minor traffic offenses, Cmdr. McCall said.

Britt's family reacted with sadness to the news that a caregiver at the Garden Terrace facility is suspected in her killing.

"Today we are saddened to learn a worker from the care facility she was visiting that night has been arrested in connection with her death," the family said in a prepared statement. "The Britt family would like to publicly thank the police officers, detectives, investigators, and prosecutors for their non-stop work to bring about this arrest."

Jim Dupree, a friend and neighbor of Jane Britt, said, "Reaction was absolute relief that we had a person who was walking around that would do a crime like this and thankfully the quality of the Federal Way Police Department was able to solve this. I'm ecstatic."

Investigative efforts by the Federal Way Police Department are continuing.

Anyone with information pertaining to this investigation is urged to contact the Federal Way Police Department's Detective Doug Deyo at (253) 835-6891.