LEWISVILLE, Texas (CBSDFW.COM) – A $10,000 reward is now being offered in the search for two suspects involved in the murder and armed robbery of a Valero store clerk.

Lewisville Police Department detectives continue interviewing a handful of witnesses in the case and those witnesses have helped police create a composite sketch of one of the suspects.

Police said the man below and another man killed Ashraf Lakhani, 51, just after midnight last Friday.

sketch of suspect in Lewisville store clerk murder (Lewisville Police)

Police describe the suspect this way:

“He is described as a young adult, light-skinned, black male with straight teeth and an athletic build. His face is thin but appears fuller around the mouth. He may have dreadlocks of an unknown length.”

The only additional detail police are releasing of the second suspect is that he is “an older male.”

Lewisville Police said investigators continue reviewing the surveillance video from the armed robbery and murder. The video contains certain details only the suspects and true witnesses would know, and releasing anything beyond what is already public, risks jeopardizing our investigation.

Detectives are asking anyone who was in the area of East Corporate Drive, from southbound I-35 to 121 business, between the hours of 11:45 p.m. on February 14 and 12:30 a.m. February 15, to give them a call if you witnessed anything that may assist in the resolution of this case. Our Crime Tip Line is (972) 219-TIPS (8477).

Surveillance image of suspects during a deadly robbery at a Lewisville gas station. (Lewisville PD)

Oak Farms Dairy is offering $10,000 for information that leads to the arrest and indictments of the suspects. The reward remains in place for six months.