Robert Jackson was just finishing up dinner on Monday night when he heard what sounded like a single pop.
"We heard something that sounded like a gunshot. At first, we weren't sure what it was and when we came outside, that's when my uncle came out, and he said that somebody was shot," Jackson said.
He and his uncle came out to see several Baltimore County Police squad cars and officers canvassing the block on Vanderwood Road where 46-year-old Idrissa Derme was killed.
He was gunned down while on the clock delivering food.
"At this point, it's a classic whodunnit. We have no information to follow up on as far as these suspects go," Officer Jennifer Peach, a spokeswoman with the police department, said.
She says someone spotted Derme on the ground, but no one called in with reports of a shooting.
Because of that, Peach says investigators are having trouble piecing together a timeline, and adds Derme could've been laying there for some time.
Initially, though, officers think Derme's killer was trying to rob him.
"You really have to be on top of your game: checking your surrounding when you pull up, if it doesn't feel safe then call back the person and ask them to meet you on the street corner or on the sidewalk," Peach said warning delivery drivers.
Jackson and a handful of other neighbors on the block say they're a little shaken up and are concerned about a killer roaming through their streets.
Police are asking anyone who may have seen anything unusual or heard gunshots fired to contact police by calling 410-307-2020. Callers may remain anonymous.