( CNN ) -- Police in California say that with the arrests of 23 people this week , they are getting closer to those responsible for a string of brazen attacks against officers in a gang task force . The booby trap-style attacks believed to be targeting the Hemet Police Department began in December when , police say , a natural gas line was rerouted into the task force 's headquarters , risking an explosion . The most recent incident occurred in March , when four city code enforcement trucks were set ablaze in the Hemet City Hall parking lot . None of the 23 suspects arrested Tuesday face charges directly related to the four attacks , but police are hopeful that they will lead them to the people responsible , Hemet Police Capt . Dave Brown told CNN . `` Tuesday 's operation produced an enormous amount of property and evidence . The 23 people arrested were detained and interviewed , producing leads , and those leads are being followed up , '' Brown said . The suspects were arrested throughout Riverside County on a variety of felony and misdemeanor charges -- from possession of weapons and stolen property to outstanding warrants and narcotics . Local and state law enforcement agencies participated in the raids , in which 35 locations were searched and evidence , including 16 weapons , was seized . Read the names of the suspects . Some of those arrested have gang affiliations , Brown said , but it 's still unclear whether the attacks are gang-related . A motive is still not known . `` Motive has been a missing piece , but once the suspects are identified , we believe a motive will follow , '' he said . `` Sometimes , in gang cases , the motive is clear from the beginning . But in this case , we 're not even sure it 's a gang case , and if so , we 're not sure if one gang is operating independent of others or if there 's some sort of cooperation between the gangs . '' Hemet is one of eight local , state and federal agencies that make up the Riverside County Gang Task Force , which was formed in 2006 to address the growth of criminal street gangs and outlaw motorcycle gangs . As the county expanded and its population grew , so did the presence and reach of organized crime . Since 1997 , the number of gangs in Riverside County has grown from 266 to 391 , according to the task force 's website , and total gang membership has grown to 10,620 people countywide . Authorities believe the attacks could be related because of their close timing and identical targets , John Hall , a spokesman for the district attorney 's office , said last month . On New Years Eve , the unmarked headquarters of the Hemet Gang Task Force was filled with deadly natural gas . Two task force members detected the gas , backed away and reported it . On February 23 , a task force member at the Hemet headquarters opened a security gate outside the building , which launched a homemade zip gun attached to the gate . The weapon fired , missing the officer 's head by inches . The headquarters has since been moved to an undisclosed location , where extra security precautions are being taken , Hall said . On March 5 , criminals targeted a task force member who had parked an unmarked police car in front of a convenience store in Hemet . The officer found what appeared to be a homemade pipe bomb hidden underneath the vehicle . The attacks have drawn the attention of state and federal law enforcement , which have contributed manpower and money to a $ 200,000 reward offered in the case . The Hemet Police Department has set up a confidential tip line for anyone with information : 951-765-3897 . People can also e-mail tip to : tips @ cityofhemet.org .
Authorities arrest 23 , search 35 locations in Riverside County in probe of attacks targeting police . Police hope sweep will lead to information about those responsible for the attacks . Four booby trap-style attacks against Hemet Gang Task Force have occurred since December . - January : A man is arrested after he allegedly tried to shoot a Los Angeles County sheriff's deputy during an argument at his home near San Diego.