"I cannot tell you an arrest is imminent, and there's certainly no one in custody," St. Louis County Police Chief Jon Belmar told reporters Friday afternoon.
"The detectives are working this investigation around the clock, and they will not rest until we have a conclusion in this investigation," the chief said.
Authorities don't feel that the trail has gone cold.
"We're not there yet. We really aren't," the chief said.
"It's hard to figure out exactly if it's one day, two days or one week or whatever it is beyond that (when finding a suspect becomes more challenging for police). It's really when you begin to get the absence of credible information," the chief said.
"We're not at that point yet," he said. "We are having the ability to track down certain leads."
The shooting of two officers occurred during a Wednesday night protest in Ferguson, but authorities don't know if the suspect or suspects had any connection to the demonstrations, Belmar said.
Police have "several leads," he said.
"I think we have a pretty good general idea of where we think the shots came from," the chief added.
Meanwhile, public donations are "pouring" into police to be used toward a reward to find the gunman and any accomplices, Belmar said.
Authorities are now offering a $10,000 reward for information leading to the arrest of person or persons responsible for the gunfire upon the two officers, according to the St. Louis Regional CrimeStoppers website.
Police are studying whether to raise that reward with the donations, the chief said.
Mayor won't step down
Also Friday, Ferguson Mayor James Knowles indicated he won't be stepping down, though the police chief and the city manager have already resigned in the wake of a devastating U.S. Justice Department report alleging institutionalized racism at just about every level of Ferguson's municipal government.
The top municipal court clerk was fired earlier for sending racist emails.
"I think it's important to recognize that there's a lot of people who may be angry at the situation; there's a lot of people who are frustrated in this community with the way things have gone down," the mayor told CNN.
"But there's a lot of people who still -- and who have expressed this to me -- express confidence in both my willingness, and members of the (City) Council's willingness, to listen, to be responsive, and to make changes as necessary," he continued.
"People in the community recognize this, now ,not everybody. I didn't win every time with 100% of the vote. But I can tell you there are ways to remove me if that is the will of the people," the mayor said.
Mood of a troubled town
Meanwhile, overnight in Ferguson prayers went up, the rain came down and tensions cooled.
It was a far cry from 24 hours earlier, when tempers flared and the two officers were shot in the St. Louis suburb.
Authorities changed tactics in the aftermath of the shootings.
St. Louis County Police said it had assumed "command of the security detail regarding protests," together with the Missouri State Highway Patrol.
Ferguson Police remain responsible for "routine policing services" in the city.
A law enforcement official said after the shootings that investigators believe they have identified two people they want to question and one of them might be the shooter.
But on Friday morning, St. Louis County Police spokesman Sgt. Brian Schellman told CNN by email that "we never identified two people. Not sure how that came about. No one is in custody."
He wasn't immediately available for further comment, but his comments including "no one in custody" were echoed hours later by Chief Belmar.
Late night with the President
President Barack Obama, who appeared on "Jimmy Kimmel Live" Thursday night, condemned the attack on the officers, but said it shouldn't detract from the main issue.
"What had been happening in Ferguson was oppressive and objectionable and was worthy of protest, but there was no excuse for criminal acts," he said.
"They're criminals, they need to be arrested and then what we need to do is to make sure that like-minded, good-spirited people on both sides -- law enforcement who have a terrifically tough job and people who understandably don't want to be stopped and harassed just because of their race -- that we're able to work together to come up with some good answers."
A call for calm came at a Thursday night prayer vigil. Clergy and others gathered.
"Our hearts go out to the families of the injured officers," a statement from vigil organizers said. "Our prayers are with these officers, their families, and every victim of violence in our streets."
Although the streets were calm, the call for action remained the same.
Many in the vigil returned to the nearby protests, but the crowds were much smaller than the night before and the rain seemed to put a damper on emotions. No arrests were made, police said.
'We could have buried two police officers'
Chief Belmar said several people "have been very forthright" with investigators, but authorities haven't released the names of any possible suspects.
"We could have buried two police officers," Belmar told reporters. "I feel very confident that whoever did this ... came there for whatever nefarious reason that it was."
The shots rang out from a hill overlooking the station shortly after midnight Wednesday, at the end of a protest against the Ferguson Police Department.
Officers saw "muzzle flashes ... about 125 yards away," Belmar said.
Protesters said they had nothing to do with the shooting, saying the demonstrators believe in nonviolence.
"As the protest was dying down, someone, somewhere got violent. Now who they were and what group they were affiliated with, we don't know," said Antonio French, a St. Louis alderman. "In no way are they representative of the thousands of people ... who have been protesting."
In the cross hairs
Belmar believes someone targeted the police, who have faced heated criticism for months, for a reason. "These police officers were standing there, and they were shot just because they were police officers," he said.
That department has been under fire since one of its officers, Darren Wilson, shot and killed African-American teen Michael Brown in August, and more recently since a scathing U.S. Department of Justice report documented a pattern of racial discrimination. Police Chief Thomas Jackson resigned
While the demonstrators' focus was Ferguson, neither of the wounded officers works for that police department.
One is from Webster Groves, another St. Louis suburb 13 miles south of Ferguson. The officer -- a 32-year-old with seven years' experience -- was shot at the high point of his cheek, just under his right eye, Belmar said.
The other was hit in the shoulder and the bullet came out the middle of his back, Belmar said. He is a 41-year-old officer with the St. Louis County Police who has been in law enforcement for 14 years.
Both men were treated and released.