YAKIMA -- DNA evidence usually gets headlines in murder cases and sex crimes.
But the discovery of cigarettes butts at the scene of a robbery outside Toppenish last year illustrates the potential DNA has for becoming an everyday crime-fighting tool.
It took nine months for results, but now three people are in custody and a fourth is being sought.
"It's a little unusual," said Stew Graham, chief of detectives for the Yakima County Sheriff's Office. "We have a few more options nowadays."
The arrests stemmed from an incident in September that began at Legends Casino.
According to arrest affidavits, a 42-year-old Toppenish man told deputies he was approached inside the casino by two women about going somewhere for "a little fun."
The man said the trio left the casino and drove a few miles away to Becker Road. One of the women rode with him, directing him where to go, while the other followed in a maroon Jeep Cherokee.
The robbery occurred on a dirt lane off Becker when a small white car blocked the man's vehicle, which was boxed in by the Cherokee from behind. The man said he got out and was beaten and robbed by two men who had been waiting in the white car. They took his wallet and his money -- $47.
The man later showed detectives the scene. Several spent 9 mm shell casings -- one of the assailants fired several times in the air, the man said -- were recovered along with several cigarette butts. A number of footprints were noted.
The cigarette butts were submitted to the Washington State Patrol Crime Lab for testing. Meanwhile, detectives reviewed security footage at Legends and confirmed the man had left with two women, including one in a maroon Cherokee.
Two weeks later, casino security spotted a similar-looking Cherokee in the parking lot and called the sheriff's office. A deputy stopped the Cherokee and spoke to the occupants, a man and a woman. Lacking probable cause, he had to let them go.
In April, the DNA results from the cigarette butts started coming back. The results matched three people in the area whose DNA already was on file with authorities in connection with other criminal cases.
The first was Rosenda S. Strong, 25, of Toppenish. Using the casino security footage, detectives identified her as one of the women seen leaving with the victim.
The other two names belonged to young men from the Toppenish area. One of them, 28-year-old Daniel C. Gonzalez, turned out to be Strong's boyfriend. The other, 22-year-old Sergio Cervantes, was the man the deputy had stopped in the Cherokee months earlier but had to let go.
The fourth suspect is Cervantes' girlfriend and driver of the Cherokee, deputies said.
She still is being sought.