( CNN ) -- The police chief of Tulsa , Oklahoma , offered a stern , succinct message Saturday to the man he believes killed three people and critically wounded two others in a spate of seemingly random shootings : `` We 're coming for you . '' Chief Chuck Jordan described the shootings at four separate sites -- all of which occurred early Friday within two to three miles of each other -- as `` vicious and cowardly attacks . '' A survivor described the suspect as a white man , driving an `` older '' white pickup truck , according to Jordan . Police Capt . Jonathan Brooks told CNN that such a truck had been spotted at at least three of the shooting sites , around that time . Still , Jordan indicated authorities do not know the identity of the shooter . He added , too , that a basic description of a white man driving a white truck `` alone probably accounts for 50,000 people in the city of Tulsa . '' With the assailant still at large , city leaders stressed that information from the public will be critical to cracking this case . `` To know that you ca n't walk down the street at night in your own neighborhood , that 's a terrible thing , '' said city councilor Jack Henderson , who represents the district where the shootings occurred . `` The only way that this person is going to be brought to justice is we need some leads . We need some people to come forward . We need some people to tell us what you know , what it is you heard . '' About 30 representatives from four different law enforcement agencies -- the Tulsa police , Tulsa County Sheriff 's Office , the U.S . Marshals Service and the FBI -- are on the case , as part of a newly formed task force called `` Operation Random Shooter . '' They 'll be working around the clock to solicit leads , gather evidence and conduct interviews , according to Jordan . Earlier Saturday , Tulsa Mayor Dewey Bartlett told CNN that at least 40 cruisers are patrolling the affected area . He added that officers are spending the weekend `` going , literally , door to door , and asking people if they have seen anything ( and ) what their opinions and observations are . '' What authorities do know is the first shooting occurred at 1:03 a.m. Friday , according to Brooks of the Tulsa police . That victim , 49-year-old Dannaer Fields , died at a hospital . Three minutes later , two people were shot nearby -- one of them `` pretty close to the ( gunman 's ) vehicle and the other ... a little further away , '' the police captain said . Those two were initially in critical condition but , by Saturday evening , were believed to have improved to stable and are expected to survive , according to Brooks . Then , just before 2 a.m. , a fourth shooting incident -- like the first , a fatal -- occurred . The third person killed was found around 8 a.m. next to a funeral home in a more commercial district , though Brooks said police believe he was shot much earlier . In addition to Fields , Jordan identified the other two victims as William Allen and Bobby Clark . `` It appears all the victims were out walking or in the yard , '' Brooks said . `` This ( happened in ) a residential neighborhood , predominantly single-family dwellings , except for the last victim . '' All the victims were black . The Rev . Warren Blakney , a pastor at a city church and president of the NAACP 's Tulsa branch , said the shootings could well prove to be hate crimes given that they happened in a predominantly African-American neighborhood . `` For a white male to come that deep into that area and to start indiscriminately shooting , that lends itself for many to believe that it probably was a hate crime , '' Blakney told CNN . Brooks , the police captain , said one survivor recalled how `` the suspect drives up to him , asks ... for directions and shoots him for no reason . '' There is no indication the shooter used a racial slur or said anything else that might indicate his motive , according to police . Jordan acknowledged it is a `` very logical theory '' to assume they were targeted in hate crimes , but said that `` we have had no evidence '' yet to indicate that . `` Right now , I 'm more worried about three of my citizens being murdered , '' the chief said . `` And if it takes us in a direction of a hate crime , that 's certainly where we 'll go and we 'll prosecute him for that as well . '' Tulsa 's mayor commended city residents for already having `` really come together , '' intent on helping capture the killer . `` It should be concerning to all Tulsans , because we are all in this together , '' Bartlett said . `` Some of our fellow Tulsans have been pretty violently shot , and some of them are not here today to enjoy the weekend with their families . '' CNN 's Nick Valencia and Don Lemon contributed to this report .
NEW : The two survivors ' conditions are thought to have improved , a police captain says . They were among five black people shot , three fatally , early Friday in Tulsa , Oklahoma . Tulsa 's police chief asks for the public 's help in finding the suspected gunman . An NAACP leader suspects it 's a hate crime , but the chief says there 's no proof of that yet .