By Steve Beck, Walt Hunter
PHILADELPHIA (CBS) -- Philadelphia police released additional surveillance video Tuesday of two suspects wanted in the murder of an off-duty officer this past weekend.
Police Commissioner Charles Ramsey announced the reward now stands at $118,000 for information leading to the arrest and conviction of the suspects responsible for the murder of Police Officer Moses Walker.
Detectives have been working around the clock to solve the murder of Officer Walker. The 19-year veteran of the police force was shot and killed during a robbery attempt near 20th and Cecil B. Moore.
Police say Officer Walker had just left his precinct after his shift early Saturday morning and was dressed in civilian clothes when he was approached by two males. Surveillance cameras in the area captured images of two men following behind the officer. Officer Walker is seen looking over his shoulder several times before being gunned down.
"It looks like they're just walking down the street, they see what they believe to be a target and they pounce on him," said captain James Clarke.
Police said the suspects apparently announced a robbery, before shooting Officer Walker three times; once on the stomach, chest and hand. He was taken to Hahnemann University Hospital where he was pronounced dead.
Police believe the suspects live in the area and are urging anyone with information to come forward.
"We would hope that people would step up and help us get two violent people off the street. These guys will rob again. They will kill again if they're not taken off the street," Ramsey said.
As police officers stopped cars and civilians, interviewing them, members of the Guardian Angles handed out fliers near the murder scene encouraging neighbors to help identify the killers on the video.
Some people, who wish to remain anonymous, can see why officers have yet to make an arrest despite a high reward.
"They're probably scared if they snitch, somebody will come after them," said one man.
Officials say the $118,000 reward is expected to grow. Twenty thousand dollars is from the city, which is a standard amount always offered for information leading to an arrest and conviction in a homicide.
Ramsey says officer Walker's shooting is a reminder of the all-too-familiar violence on the streets of Philadelphia.
"Our homicides and shooting are up this year compared to last, as you well know. This is just one more tragic incident, but every loss of life is tragic, and every single family that's involved in this is grieving, and our police family is grieving like those other families are grieving."
The first suspect, who police believe is the shooter, is described as a black male, bald head, possibly with a beard or goatee. He was wearing a light-colored hooded sweatshirt and dark-colored shorts.
The second suspect is described as a black male wearing a dark-colored hooded sweatshirt and dark-colored shorts.
If you have information about this crime, call 215-686-TIPS.
for more features.