JACKSOVNILLE, Fla. -- Two of the three teenagers facing charges of felony murder and armed robbery during a fatal police-involved shooting appeared before a judge Monday.

Richard Douglas, 16, and Kenneth Duncan, 17, were in court for a Monday morning arraignment. The third suspect, 17-year-old Robert Wallace, has already been arraigned and has pleaded not guilty.

A fourth armed robbery suspect, 17-year-old Kenneth Marion, was shot and killed by police on the night of the alleged crime.

According to police, all four teens took part in the Feb. 21 armed robbery of a Gate gas station on Hendricks Avenue that led to the death of Marion.

Police said an off-duty sheriff's officer saw the teens running from the scene of the robbery. Another officer, who also gave chase, claimed he saw Marion reach for a gun and opened fire, killing the 17-year-old.

According to authorities, two guns were found near the scene.

In court Monday, Duncan entered a not guilty plea. Douglas, who was also scheduled to appear before a judge, was not able to enter his plea because his attorney was not present.

The three teens allegedly with Marion the night of the robbery have been charged with murder because they were allegedly committing a felony when Marion was shot and killed by police.

The teens are also charged with two counts of armed robbery.

The next hearing date in this case is set for April 1.