New leads and details in the shooting death of a 25-year-old correction officer who just joined the force. Criminal Justice Reporter Dean Meminger has this follow-up and information on other cases involving correction officers.

Police are a step closer to finding out who killed off-duty rookie correction officer Alastasia Bryan.

Surveillance video, see in the video above, shows a man walking up to her car and firing five times.  Sources say the NYPD has a person of interest they want to question — a person who Bryan knew.

"Everything goes through your mind," said Joseph Ponte, the commissioner of the department of correction (DOC). "Is it an assassination, is it a gang, is it related to work?"

It happened Sunday night in Brooklyn, while Bryan sat in her parked car near her mom's house on East 73rd Street and Avenue L.

Police believe two people were staking out the young correction officer who worked on Rikers Island for only a month.

Police say the men were last seen in a tan Hyundai Elantra.

The correction department says although the shooting doesn't appear to be related to her work, officers are encouraged to to watch their backs.

"It is a dangerous job, we work with dangerous felonies day in and day out," Ponte said. "Sometimes that carries to outside of work and that is a risk we put our staff in every day."

"If staff does feel threatened outside of the work environment, we do have procedures in place that we can provide security for them," said Martin Murphy, the DOC chief of department.

Police are encouraging people to take a very close look at the surveillance video, and they say you should contact them if you know anything about this shooting.

Detectives are trying to get information from Bryan's cell phone, but NY1 is told it was damaged in the shooting.

The correction department has also been concerned about a missing veteran officer, but Friday afternoon Ken Smith was found in Harlem disoriented.

He left his Mount Vernon home Wednesday, heading for work but never made it.

"We had contact with the facility," Ponte said. "He talked to, I believe, one particular officer a couple of times during the course of the day. Then there was no additional contact."

Smith is back home with his family, and NY1 is told there's a break in another case involving a correction officer.

Henry Wright, who worked in the state system, and his wife, were shot and injured when someone invaded their Queens home last month. An arrest has been made, but the investigation continues.