It wouldn't come to that, because the whole claim is beyond idiotic.
If Seattle had gangs that were capable or planning such attacks, the police would watch them well. This came out of the blue. NOTHING about these attacks would even make you suspect gangs for a minute. The lack of suspects, arrests or dead attackers alone is too mysterious.
If a gang made such an effort, it would be BECAUSE they wanted to leave their signature. Territorial pissings. Instead, they make ninja-like assaults and escapes without getaway cars, yet without any type of motive or direction. They move like an epidemic. It's erratic slaughterfests that weren't aimed at robbery, plundering, drugs or even to establish turf or decimate another gang. Otherwise gang members would be targeted. Break ins would happen without tools or subtle backdoors, but by barging through front doors with brute force clearly above human capabilities. No shootouts or knife attacks, not even signs of prolonged struggles.
If there were corpses, any coroner would instantly blow the gang claim out of the water. Even if you assumed that every victim was drank dry and then either disposed of (somehow without remains) or hindered from running off frenzied or fleeing after being turned, this only makes gang violence less likely. Why and how would a gang abduct so many random, unconnected people without ransom, and how do they get away so easily by foot?
A gang attack doesn't leave unanswered questions, but landslides of unsurprising evidence, suspects, arrests, shootings, motives. You cannot possibly mistake overpowered frenzied bloodlusting vampire carnages with gang violence. There would also be plenty eyewitnesses watching and recording things out of their homes.
Thats not even the worst. They sunk a CRUISER. What gang causes such collateral damage, unarmed even, and why, and how would the police not have a clue who did that? Is the NSA too busy checking WhatsApp for national threats to even suspect terrorists in this?
In reality, when the police can't answer questions that should be obvious, the type of experts you see in 9/11 documentaries would take
every crime scene apart. They'd find out would open more questions leading away from the gang claim. Instead, old unsolved cases of vampire attacks worldwide would be scrutinised for connections. They would at least realize how powerful the attackers were and that victims turned into attackers.
Citizens and cops of Seattle would be fearing for their lives, not sure what and why it happened, and if it could happen again. Hundreds of missing people would be sought for for years. If anything still pointed to a gang, that gang would be raided, and every member questioned where these people went.
Then we have the Volturi who weren't worried about this somehow. The geniuses who lure flocks of tourists right into their doorstep. No loved ones and no home countries ever wonder where so many people disappeared on this little island? Asking the inhabitants, you probably wouldn't even have to search the whole rock, they could tell you pretty exact where the touris were last seen. It's the place that hires lots of secretaries, who often don't return from work yet nobody checks with their employers. The Volturi couldnt do this ONCE.
Let's forget about the police and assume this whole army made it undetected towards Forks, and nobody could guess their destination was the Cullen's home where they disappeared. The Cullens were worried to play baseball outside thunderstorms for the noise, yet that massive vampire/werewolf battle is quieter than the average vamp baseball game? Does nobody ever enter these woods? Where did they burn the bodies, and how was nobody worried by the massive column of smoke from the forest?
The newborn make no sense to begin with. Imagine you fell victim to them and awoke as a vampire. You unwillingly suck another innocent dry, then understand you are now a superhuman monster. Will you follow the murderous psychopaths to butcher more innocents and spread your "disease"? Why would you believe anything that ONE of them said? You would slip out and seek help. Most newborn would.
And by that, vampire existence would be revealed to the world, which would have an easy time eradicating those morons and parasites.
