The Denver district attorney on Tuesday filed charges against nine people in connection to a string of violent, racially motivated attacks in Downtown Denver over the past four months.Each of the suspects remain behind bars, held on $1 million bond."We filed the first nine of possibly two dozens cases in connection with a series of robberies and assaults that were occurring in downtown Denver," said Denver district attorney spokeswoman Lynn Kimbrough.More charges are expected to be filed against some of the 34 suspects later this week, she added.City leaders' and the police department's handling of the four-month crime, which involved 26 violent attacks between July 17 and Nov. 17, has sparked controversy.Police did not publicly acknowledge the crime wave in the popular downtown entertainment district until 7NEWS requested crime records for the area on Sept. 3 -- two months into the attacks. At the time, police spokesman Sonny Jackson said police did not alert the public of the possible threat earlier because "we have to have a pattern of behavior."By early September, a special FBI task force out of Washington, D.C., had been working with police to try and solve the crimes -- which have been random but violent.On Tuesday, Denver talk-radio host Dan Caplis and callers were criticizing Mayor John Hickenlooper and police for failing to publicize the attacks sooner, accusing officials of a "cover-up" that put downtown visitors -- unaware of the racially motivated attacks -- in jeopardy. "I'll be very interested to hear what the mayor has to say about why we were denied that information we needed to make our own self-protection decisions," Caplis said on KHOW. "The mayor should be very public, he should be warning people ... Instead what we got was a cover-up. And your safety was put at risk."Hickenlooper and Denver council members expressed satisfaction that the public received adequate warnings of the downtown attacks, even if police waited two months before informing the public about the attacks, the Denver Post reported Tuesday."They (the police) worked very quietly," Hickenlooper said in a Monday appearance with radio-talk-show host Mike Rosen, in response to a caller's question. "Nobody told me about this investigation, that they had made progress."Hickenlooper suggested in the radio interview that police stayed quiet about the investigation to help round up the suspects."They used one kid to get to another kid," the mayor said. "They wanted to bring down this whole extended gang at one time, and I think they've done, obviously, a good job of doing that."Tuesday's formal charges revealed more about the brutal nature of the attacks, in which lone victims were often blindsided by a gang of assailants. But police have had arrest affidavits sealed, holding back information about the attacks and what police knew and when.Of the nine charged Tuesday, Ashley Celestine, 17, and Rodney Christopher, 18 are charged with aggravated robbery and first-degree assault in connection with an incident on Nov. 9 at 1550 Broadway. The charges allege the suspects attacked a 25-year-old man from behind, knocked him unconscious, violently assaulted him, and stole his cell phone.Kavean McCloud, 17, and Alexander Bunting, 18, are charged with first-degree assault and conspiracy to commit first-degree assault in connection with an incident on Sept. 6 at 17th and Market streets. The charges allege that McCloud assaulted a 24-year-old man as part of an initiation process encouraged by Bunting, Kimbrough said.As a result of the attack, the victim suffered a head injury that included a skull fracture.Celestine and McCloud are both being charged as adults.Kendall Austin, 18, and Clarissa Lockhart, 19, are charged with attempted robbery, bias-motivated crime, and third-degree assault in connection with an incident on Sept. 4 at 16th and Welton Streets. The charges allege that the defendants attacked two men in an attempted robbery."These (bias-motivated) charges are basically alleging that as part of the attack there was intent to harass or intimidate based on race," Kimbrough said.Nyeri Goff, 19, and Landae Woods-King, 21, and Tabias Graves, 18, are charged with attempted robbery, conspiracy to commit attempted robbery, and third-degree assault in connection with an incident on Aug. 11 at 30th Avenue and Downing Street. The charges allege that the defendants attacked a man at the bus station in an attempt to rob him.Police have linked 26 attacks on white and Hispanic men to this group of suspects, who are all black.The attacks, dating back to July, usually involved the alleged gang members blindsiding the victim, beating them and robbing them. They sometimes taunted them with racial insults during the attack, according to investigators.The suspects allegedly stole wallets, iPods and cash and may have sold videotapes of the crimes as entertainment.One suspect -- Allen Ford -- remains at large. If you have more information about this story, or are a victim of these crimes, contact 7NEWS at 303-832-0200 or e-mail us at email@example.com.