A "very, very successful gang sweep" took nearly 80 fugitives off the streets — 57 in the Tri-Cities alone — along with eight firearms, hundreds of rounds of ammunition, a variety of drugs and about $14,000 cash, authorities said Friday.

More than 100 officers from 20 agencies participated in a three-day warrant round-up that concluded Friday as part of Operation Valley Thunder, a joint law enforcement operation that involved local, state and federal agencies.

Of the 57 arrested in the Tri-Cities, 19 were juveniles and 16 were picked up on immigration violations, officials said. Another 21 fugitives were jailed in Yakima.

"This gang sweep was initiated because of the terrible gang problem we've been having" in the Tri-Cities, Yakima and Grant counties and Spokane, said James McDevitt, U.S. Attorney for the Eastern District of Washington. "Criminal gang activity is the cancer that eats away at Eastern Washington and society in general."

McDevitt called the warrant sweep a "near-perfect operation" while announcing the results at a joint news conference at the Kennewick police station.

He was joined by police chiefs from Kennewick, Pasco and Richland, prosecutors from Franklin and Benton counties, representatives from the Benton-Franklin juvenile detention center and state Department of Corrections, and the assistant special agent in charge for U.S. Immigrations & Customs Enforcement in Spokane.

It's the second warrant sweep in the Tri-Cities since July, when Operation Clean Sweep targeted gang members and officials released a list and pictures of 28 gang-involved fugitives that were sought.

Pasco Police Chief Denis Austin said similar efforts are going to be repeated until criminals realize gang activity is not going to be tolerated here.

"Those gang members are going to need to change the way they behave — the way they react — or we're going to be knocking on their doors," Austin said.

The eight-week operation targeted street-level and mid-level drug traffickers, illegal aliens and fugitives in the Tri-Cities and Yakima Valley who are known gang members or have ties to gangs, authorities said.

Tri-City officers targeted 100 fugitives mostly residing in Kennewick and Pasco and served 20 early-morning search warrants.

"We're working to put people in jail," said Kennewick Police Chief Ken Hohenberg. "Our primary mission is to make a safer Tri-Cities."

County prosecutors will be working with federal prosecutors to determine who's best to handle the different cases. Sentences —depending on the crime, where the case is prosecuted and the defendant's criminal history — can range from a few months to a few years at the state level to 15 years or more in federal court, McDevitt said.

ICE officials will also process foreign nationals for deportation.

Strict enforcement is key to cracking down on criminal gang activity, officials said, but it's only one part of the solution.

"We can't prosecute our way out of every crime problem," McDevitt said. "For every $1 in prosecution we need to spend $1 in prevention. … A good dose of prevention won't eliminate (the problem), but it will minimize it."

Sustainable criminal justice funding and support from local legislators is also essential, the Tri-Cities' top law enforcers said.

Money, for example, is needed to expand the Franklin County jail so there's a place to keep criminals locked up and off the streets, and budget cuts are hurting programs like drug courts and offender supervision, they said.

A check of the criminal history of the 16 juveniles arrested this week showed they had a combined 73 prior misdemeanor convictions, 23 prior felony convictions and 71 probation violations, said Dave Wheeler, the juvenile justice center's community supervision services manger.

Some of those repeat violations may have been prevented had the Selective Aggressive Probation program not been cut back, officials said. The SAP program provides intensive supervision to some of the counties' most serious, repeat juvenile offenders. But a SAP officer's job was lost because of funding cuts, so the number of offenders being supervised also was reduced.

"The SAP program is extremely effective," Austin said. "They had direct supervision of some of the highest-profile gang members on a daily basis and we saw a decline (in gang activity) and gang members got out of gangs."

Fighting gang activity also requires partnerships across local, state and federal levels and between regional communities so the problem isn't simply pushed from one county to another.

"Gangs are very mobile, very fluid. Grant County has been eaten alive (by gang activity)," McDevitt said, adding that's why "it isn't any good to do this kind of activity in just one community."

The Tri-Cities may not be seeing the amount of serious gang activity that Yakima County is seeing — authorities this week investigated the 20th homicide of the year — but many of the drug crimes, graffiti, burglaries and thefts can be linked to gang activity, officials said.

Hohenberg likened it to a pot of water that's "just simmering. It hasn't boiled over yet, but it's still simmering."

That's why they're working together, conducting sweeps and sharing intelligence to try to eliminate the problem before it escalates.

"Our message is the Tri-Cities is a bad place for people to come if you want to be involved in criminal gang activity," Hohenberg said.