ARLINGTON (CBSDFW.COM) — Police in Arlington are searching for the person who stabbed a husband and wife, one of them fatally, during a robbery on Sept. 30 and who may be linked to other recent violent crimes.

Officers were sent to the 6400 block of South Collins Street just after 9:00 p.m. Once there they found the victims both suffering from stab wounds. The pair was taken to a local hospital, but the man, a 47-year old later identified as Islam Sahmi Duly, was pronounced dead at the hospital.

Police say the female victim is still being treated for serious injuries. The woman told investigators that her husband was pushed to the ground by the attacker. She said the robber punched and stabbed her several times, before going back to her husband, demanding personal property and stabbing him again.

“We are really needing the public’s help on this case to bring the person on persons responsible to justice,” said Interim Police Chief Kevin Kolbye. “Our hearts go out to the victims and families impacted by these acts of violence.”

Investigators say the male suspect — who they are still looking for — ran from the scene on foot towards the Dollar General Store at 1200 Southeast Parkway.

Police believe that after the stabbing the same suspect was the driver of a vehicle that hit another woman while she was walking her dog in the 900 block of Southeast Parkway. Investigators say the woman was injured by the vehicle, as it turned onto Rising Meadows Drive, and her dog was killed.

“The woman who is now lifeless, lying on the grass, hears one of the suspects yell, ‘grab her wallet, grab her wallet.’ And so she realizes this is not just a crash, they’re going to try to rob her,” Lt. Chris Cook said.

Police are also going back to a stabbing and robbery from last Monday at a convenience store, where a clerk complied but was still stabbed. Police believe that type of violence after the victims cooperate is unusual — and so is the use of a knife as a weapon.

“This guy has no regard for human life. He could have killed all three of these people,” Cook said.

Detectives are asking residents in the area from South Collins Street, Southeast Parkway and Rising Meadows Drive to check their security video systems to see if they captured the fleeing vehicle. Investigators believe the suspect fled westbound on Southeast Parkway from South Collins Street.

Police are asking that anyone with information about the attack or the wanted suspect, no matter how insignificant it may seem, call homicide detectives at 817-459-5735. Tipsters can remain anonymous by contacting Tarrant County Crime Stoppers at 817-469-TIPS.