Aaron Cody Smith (MCSO)

The Montgomery police officer who fatally shot Gregory Gunn in the early morning hours of Thursday, Feb. 25 is charged with murder.

Officer Aaron C. Smith, 23, was arrested Wednesday, and his bond was set at $150,000, Montgomery County District Attorney Daryl Bailey said during a Wednesday afternoon press conference.

"SBI and I agreed at the beginning of this investigation that this case would be treated as any other case," Bailey said. "We agreed that if there were probable cause that a crime had been committed then an arrest would be made. After meeting extensively with SBI agents, we have concluded that probable cause exists to make an arrest in this case."

He said the arrest isn't an indictment, and the investigation remains ongoing.

Smith, a Montgomery police officer since 2012, was released on bond shortly after being booked into the Montgomery County Detention Facility on Wednesday afternoon.

Gunn was fatally shot on Feb. 25 at around 3:20 a.m. in the 3200 block of McElvey Street in the west Montgomery neighborhood of Mobile Heights.

Last week, Montgomery Police Chief Ernest Finley said the incident began after an officer stopped to talk to a "suspicious" person, later identified as Gunn, and an altercation ensued. It was initially reported Gunn was armed with a painting pole or stick.

It's unclear now why Gunn was deemed suspicious, or if he was really armed with a stick.

Montgomery Mayor Todd Strange said today that termination proceedings have begun against Smith.

Residents of the Mobile Heights neighborhood -- where Gunn grew up -- reported hearing multiple gunshots in the early morning hours of Feb. 25 and Gunn calling for his mother, with whom he was living following a divorce.

Some community members had called for action, some even asking for white police officers not to patrol in black neighborhoods, following the shooting. Gunn is black. Smith is white.

About a dozen protesters caused Tuesday night's Montgomery City Council meeting to adjourn early.

Local attorney Tyrone Means, who represents the Gunn family, told the Associated Press that on the night of the shooting Gunn had attended a card game with friends after he got off work. Gunn frequently walked from his friend's house to his mother's home a few blocks away, he said.

"Trayvon Martin was a black kid walking in a predominantly white neighborhood, and someone just thought he looked suspicious," Means said. "Greg Gunn was in a community in which he was well-known and well-loved. That's scary."

Smith's attorney, Mickey McDermott, told WSFA this afternoon that the arrest of his client came as a surprise. Normally in these types of cases, the evidence would be presented to a grand jury before an arrest is made, McDermott said.

McDermott said Smith has cooperated with the investigation and he believes Smith was justified in using deadly force as he felt his life was in danger.

"Mr. Gunn chose to run from a Montgomery police officer during a field investigation and he fought the police officer for a great length of time," McDermott said. "Mr. Gunn became violent."

He said "no one has more empathy for Mr. Gunn" than Smith.

McDermott said Smith has received death threats, and his family will have to go into hiding.

Today, Bailey said many members of the community are sharing rumors online and with the media, but he declined to dispel those rumors.

"I can assure you that most of the things you have heard reported by the news and on social media are completely untrue," he said. "The facts will come out in the court of law."

Bailey asked the community to stand behind the police department.

"I want to be crystal clear that the arrest warrant secured against Officer Smith is in no way an indictment against the Montgomery Police Department," Bailey said.

"In fact, 99.9 percent of the officers at the Montgomery Police Department do an exceptional job on a daily basis making sure that our citizens are protected. They are in fact the thin line between order and chaos. I encourage this community to rally around the police at this time and let them know that they are appreciated. This is an isolated incident that will be dealt with, as it should be, in the criminal justice system."

Strange said he had asked the State Bureau of Investigation to expedite the investigation into the shooting.

"We cooperated fully (with the SBI investigation)," Strange said during today's press conference. "We will continue to cooperate fully as it moves forward."

He said Montgomery police didn't investigate the shooting. The scene was isolated, and the investigation immediately handed over to the State Bureau of Investigation.

No details of the case, including what may or may not be on the officer's body camera were released to Strange, Finley or Montgomery Department of Public Safety Director Chris Murphy, Strange said.

"This is a time of grief for the Gunn family as they prepare to lay a loved one to rest," Strange added later. "It is also a challenging time for MPD ...."

Strange said hopes to speak with Gunn's mother and to offer his condolences.

In an early Friday morning press conference, Finley said the incident began when the officer noticed a suspicious looking man, later identified as Gunn, walking on McElvey Street. The officer stopped to talk to him, Finley said.

That's when a struggle between the officer and the man occurred, he said. The struggle lasted for about a block before the officer fired a shot at the man and killed him.

Finley said at the time, Gunn was believed to have been armed with a painting pole or stick.