( CNN ) -- The Cherokee County Sheriff 's Office on Friday released a second sketch of a man believed to have fatally shot four people in less than a week near Gaffney , South Carolina . Police say the suspect may be driving a light-gray or champagne tan 1991-1994 two-door Ford Explorer . `` Let me say that , under the FBI 's definition of a serial killer , yes , we have a serial killer , '' Sheriff Bill Blanton told reporters in Gaffney , a town in the county of about 54,000 residents some 50 miles southwest of Charlotte , North Carolina . He would not detail what has led investigators to conclude the shootings are linked or how they received the description of the suspect that has led to the two sketches . In addition , he said he did not know whether the shooter knew his victims or whether he may have chosen them at random . Police said he may be driving a light-gray or champagne tan 1991-1994 two-door Ford Explorer . The first shooting happened Saturday , when peach farmer Kline W. Cash , 63 , was found dead by his wife in their home , said Leigh Caldwell , a victims services coordinator for the sheriff 's office . Blanton said Cash 's home may have been robbed . On Wednesday , the bound and shot bodies of 83-year-old Hazel Linder and her 50-year-old daughter , Gena Linder Parker , were found in the mother 's home , where she lived alone . `` We 're still trying to determine if anything 's missing from there , '' Blanton said . Thursday night brought two more shooting victims -- 45-year-old Stephen Tyler was found shot dead and his 15-year-old daughter wounded in the family-run furniture and appliance store , Tyler Home Center , said Chief Rick Turner of the Gaffney Police Department . He would not say whether the Tylers were bound . The daughter remained hospitalized Friday , Caldwell said . Leave has been canceled for all members of the Police Department and the Sheriff 's Department , said their respective chiefs , who urged residents to take precautions . About 100 investigators from North and South Carolina were working the case , Blanton said . `` I think our community has a right to be concerned , '' he said . `` We 're concerned . We 're dealing with a man that 's killed four people . '' He urged residents to check on relatives , especially those who live alone . `` We 're asking the people in our community to be vigilant , to report anything . '' But he cautioned against taking that too far . `` Our concern is that people are going to start shooting at shadows , '' he said . In a separate incident , police looking for the shooter tried to stop a dark SUV Chevrolet Blazer and wound up with yet another killing , this one apparently self-inflicted . `` The driver , who the officer did n't know at the time was a female , pulled over , '' Blanton said . `` The passenger door opened ; two children got out with their hands up . '' The children were in their early teens , he said . `` The mother takes off . The officer gives chase thinking maybe she 's the suspect . Shots were fired during the chase . '' As police cars converged on the SUV , `` Somewhere in the middle she takes her own life , '' he said . `` Right now , we 're working it as a self-inflicted gunshot wound , suicide . '' Blanton said narcotics were found in the car driven by the woman , whom he identified as a 35-year-old woman from nearby Blacksburg , South Carolina .
Man fatally shoots 4 people in less than a week near Gaffney , South Carolina . `` Under the FBI 's definition of a serial killer , yes , we have a serial killer , '' sheriff says . 100 investigators from North and South Carolina working the case . Woman apparently kills self after police stop her while looking for shooter .