DETROIT (WWJ) - Detroit police have released a suspect sketch and video in the case of a man slain outside his family's party store on the city's west side.

Just after 11 p.m. on Saturday, Sept. 21, 77-year-old Lewis Putrus was locking up D & D Liquorland on Schoolcraft Street, west of Greenfield, when a suspect approached, flashed a gun and announced a robbery.

Suspect sketch (Credit: Detroit Police Department)

Police said Putrus complied, and the suspect then turned to a 56-year-old witness, demanding money from him, too.

That's when a second suspect came from around the corner of the building towards Putrus. The witness told police he heard two or three gunshots before the suspects fled westbound on Schoolcraft.

Putrus, who was shot multiple times, died at the scene.

The shooter is described as a black male mid to late 20s, 5'8'' tall and around 150 lbs., with a slim build, dark brown eyes, medium brown complexion, beard and goatee. He was wearing a white baseball cap, black hooded sweater, black jacket with two white stripes on the right arm of jacket and black pants.

As the investigation continues, the nonprofit Midwest Independent Retailers Foundation is offering a $10,000 reward for the tip that lead to the arrest and conviction.

"These senseless killings need to stop," said MIRA president and Auday Arabo. "Why can’t these criminals take the money and just go? Many store owners help out a lot of their customers in the neighborhoods; they serve and give or loan money at various times when people are in need. There was no reason to kill this 77-year-old grandfather of 10."

Anyone who recognizes the suspects or who has any information that could help investigators solve this case is asked to call the DPD's Homicide Unit at 313-596-2260. Or, to remain anonymous, call the Crime Stoppers tip line at 1-800-SPEAK-UP (1-800-773-2587).