Trooper First Class Wesley Brown, 24, was working security at the Applebee's on Donnell Drive overnight after finishing his shift.
As Brown stepped out the front door to make a phone call, a gunman lurking in the shadows near a bus stop on Donnell Drive opened fire.
Law enforcement sources say the gunman fired seven times, hitting Brown with all seven rounds from a distance of about 70 feet. One of the bullets struck Brown's side, which was not protected by his body armor, the sources said; that bullet struck his heart.
"The trooper, it doesn't appear to us, even had a chance to draw his weapon or fire," said Maj. Andy Ellis, a Prince George's County police spokesman. "It appears he was ambushed."
Trooper Wesley Brown Brown stumbled into the restaurant where he collapsed. He was taken to Prince George's Hospital Center where he was later pronounced dead.
The investigation quickly focused on a man Brown had thrown out of Applebee's a half-hour before the shooting. He was described as a black male, 25 - 30 years old, 5'7" tall, weighing 130 pounds, with a dark complexion, short hair, and slight facial hair.
He may wear glasses and was last seen wearing a baby blue Hugo Boss short sleeve shirt with a midway zipper and blue jeans. (See surveillance photos to the left.)
After the shooting, the same man was seen running from the scene toward an apartment building on Donnell Drive.
All day, heavily armed officers combed the neighborhood but they did not find the man.
But investigators aren't certain the man who was ejected from the bar was the gunman, sources say. Police are urging the man to come forward.
Maryland State Police Superintendent Terrance Sheridan says the gunman needs to know the consequence of his actions.
"What he has done is devastate his family, and all of those people he's protecting, day in, day out," Col. Sheridan said. "When this happens it goes against our society that we all stand for."
Family members were notified of Brown's death about 4 a.m.
His sister, Patrice Faison, focused on Brown's work as a mentor to children in his community, "using his own money, to provide education, trips for the young boys," she said. "For a lot of them, Wesley was their father."
Anyone with information about the man in the surveillance video's identity is asked to call the Prince George's County Police Department's Homicide Unit at (301) 772-4925.
Callers wishing to remain anonymous may call Crime Solvers at 1-866-411 TIPS (8477) or text "PGPD plus your message" to CRIMES (274637).
You can also go to the Prince George's County website and submit a tip online.
There is a total of $50,000 in rewards being offered for information leading to an arrest and conviction in this case.
Trooper Brown was the 42nd Maryland State Police trooper to die in the line of duty.