Authorities are asking for the public’s help as they continue to search for the person responsible for killing the owner of a Neptune City convenience store owner during a robbery more than 28 years ago. Smita Amin Patel was stabbed to death inside her business — the Little Brown Jug — on Route 33 in Neptune City shortly before 10 a.m. on March 22, 1996, authorities said at the time. She was able to call 911 before she died from multiple, deep stab wounds of the neck and chest, authorities said. The attacker fled with cash and lottery ticket, and her body was found by a customer, authorities s…