Donald Arthur Berstler, 75, of Lakeside, CA, passed away peacefully on March 11, 2018, at Bosworth Gardens Assisted Living with family members by his side. Don was born and raised in Morristown, NJ. He was the oldest of his two siblings, Richard and Bette. Upon graduating high school in 1960, he joined the Marine Corp bringing him out to San Diego. There he met and married Mary Green, and fathered two children, Don Jr. and Sandi. He served time in the Marines before being honorably discharged. There he received many awards including Good Conduct medals and a Sharp Shooter badge. After that, his dream of becoming a police officer came true. He worked for the San Diego PD and National City PD. Legend tells that he was quite the undercover cop! During his career he received many awards. After retiring, he became a private investigator. He was a member of CALI (California Association of Licensed Investigators) and received high recognition. In 1998, Don met Grace Ames and they got married in 2002. His many hobbies over the years included: bowling, men's softball league, golf, fishing, hunting, traveling, working on his many boats, trucks and old Jeeps, and loving his ten grandchildren. In 2012 he was diagnosed with Vascular Dementia. We will miss him dearly and hold him close in our hearts. Because of Don's faith in Jesus, he is in heaven now as an undercover angel cop, continuing his love of surveillance. Don was preceded in death by his mother, father, and long-time partner Geno Ciolli.