Neighbors grew worried when they hadn't seen Nancy Boehm and her mentally impaired son, Shawn, walking around their North Hollywood neighborhood back in September 1997.
Their worst fears were realized when a friend discovered mother and son stabbed multiple times inside the home they had shared for more than 20 years.
The slayings went unsolved for 12 years.
On Thursday, Los Angeles Police Department detectives announced that a felon serving time in state prison was suspected of the crime. The suspect is serving time for the fatal stabbing of a woman in North Hollywood in 2001.
Boehm and her son were found stabbed and slashed to death in separate bedrooms of their Riverton Avenue home.
DNA was collected from the scene, but computer technology wasn't developed enough to quickly and effectively analyze the evidence.
Neighbors said Boehm was an assembly-line worker for General Motors until she was laid off several years before her death. Shawn Boehm, who had played basketball in the Special Olympics, was often seen riding his bike or walking along the street, neighbors said at the time.
Initially, detectives pursued the theory that Nancy Boehm was targeted because she was selling drugs to supplement her income. But the case went cold, and police never identified any suspects.
Four years later, Rafael Martinez, 37, was arrested in connection with the fatal stabbing of Luz Nieves in her North Hollywood home, a few blocks from the Boehms' home.
Martinez was later sentenced to 14 years in state prison
In subsequent years, homicide detectives began to review cold-case slayings in hopes of using new technology to solve them.
A few months ago, North Hollywood homicide Det. Thomas Townsend asked a crime analyst to examine the evidence collected from under Nancy Boehm's fingernails. It was retested, and police got a partial match with Martinez.
That partial match, combined with how close Martinez lived to both the 1997 and 2001 crime scenes, led police to Martinez, said Lt. Alan Hamilton of the North Hollywood Division.
"Although it is often described as a cold case, we've stayed with this case because of . . . the particularly brutal nature of this murder," Hamilton said. "You basically have two people in a house, and they're basically slaughtered."
Martinez is still in the custody of the state Department of Corrections and Rehabilitation and is expected to be transferred to a Los Angeles jail to be charged in the near future.
LAPD investigators said that they believe Nancy Boehm was selling drugs and that the victim in the 2001 killing was also involved in drugs. They did not say exactly how Martinez came to allegedly target Nieves.
"It's narcotics-related, and unfortunately Shawn got caught up, and it isn't his fault. He had nothing to do with this. He is an innocent victim, and Nancy is too," Townsend said. "It's unfortunate that she had to resort to other means to supplement her income."