Police in Florida are searching for a 27-year-old man suspected of killing his grandmother and stealing her car Wednesday . Patrick Campbell was named a person of interest after his grandmother , 64-year-old Darlene Robertson , was found beaten and stabbed to death in her New Smyrna Beach home . According to police , the victim suffered blunt force trauma to the head and cuts to her abdomen . Scroll down for video . Wanted man : Patrick Campbell , 27 ( left ) , has been named a person of interest in the murder of his grandmother , 64-year-old Darlene Robertson ( right ) , who was found beaten and stabbed to death . Grisly end : Robertson 's son found her lying in a pool of blood in her living room in New Smyrna Beach , Florida , when he went to check up on her . Evidence : Police found Campbell 's bike on Robertson 's property , leading them to believe that he was at the house around the time of the slaying . Investigators say they found no evidence of a forced entry at Robertson ’ s home in the 400 block of DeSoto Drive . They believe her grandson , who has been described by friends as mentally unstable , may have been staying with her . Darlene Robertson was discovered lying in a pool of blood in the middle of her living room at around 10am Wednesday by her son , who came to check up on her after she failed to show up for work at a condominium association , according to WFTV . On a 911 call the son told the dispatcher : ' I think she 's been stabbed ... I think I can see a wound on her stomach . ' Responding officers established that Robertson , who lived alone , was last heard from at around 8.30pm Tuesday . Police have found evidence placing Campbell at his grandmother ’ s home on the night of the murder . His bicycle was found on the property . On Wednesday , police were waiting for a search warrant to enter Campbell ’ s apartment . They also have reviewed surveillance video from a neighbor ’ s home , reported The Daytona Beach News-Journal . Armed and dangerous : Campbell is described as unstable and mentally disturbed . Anyone who encounters him is urged to call police . Local authorities have issued a nationwide alert to help locate Patrick Campbell , who is considered armed and dangerous . Anyone who recognizes him is asked to call police right away , as the 27-year-old is believed to be unstable . ‘ I think that it ’ s safe to say that he is not of his right mind , ’ New Smyrna Beach Police Chief Mike Coffin said . Henry Toland , a long-time friend and former roommate of Campbell 's , described the man as delusional to the station WESH-TV . Other people familiar with the 27-year-old suggested that he may be schizophrenic . Detectives are also searching for Darlene Robertson ' missing car , a 2006 beige or tan Nissan Altima with Florida tag 803MBW . A $ 1,000 reward is being offered for information leading to Campbell 's arrest . The person of interest has a past criminal record , which includes at least four arrests since 2011 on charges of trespassing , DUI and marijuana possession .
Patrick Campbell , 27 , named a person of interest in murder of his grandmother , 64-year-old RobertsonDarlene Robertson . Woman was found by her son in a pool of blood in her New Smyrna Beach , Florida , home . Police say Darlene Robertson suffered blunt force trauma and cuts to her stomach . Campbell is considered mentally unstable and anyone who encounters him should call police .