Nearly four years after her son's burned body was recovered from an abandoned car at Kea'au Beach Park, Sharon Reverio still has no idea who killed him or how.

Her son, John A.L. Reverio, 23, was last seen alive on May 11, 2002, camping at Lahilahi Park, police said. His partially charred body was found in the bush area north of Kea'au Beach Park in Makua on May 14, 2002.

Police are actively investigating the "cold case" and are asking the public for help finding witnesses and leads.

John Reverio's life was headed for tragedy, his mother said yesterday. For months before his death, he lived on the beach while struggling to escape an addiction to crystal methamphetamine. His mother said that despite pleas from his parents and two older siblings, Reverio continued using.

She last saw her son the day before Mother's Day 2002. Authorities found his body one day before her 49th birthday.

"You never want to see anything like that (drug addiction) happen. We worried about that every day, then when something happened ... indescribable," she said by phone from the family's home in Makaha Valley Plantation. "It's really hard on any parent losing their child. The worse thing is not knowing how he passed on."

Her youngest son's passing has been hard on the family, she said. Her husband has lost more than 100 pounds since the death and is collecting disability from the government while battling diabetes.

A manager at McDonald's, Sharon Reverio, now 53, just wants the pain to end.

"We're coping the best we can," she said. "Physically we've been drained."

The Honolulu Police Department and the state attorney general's office both run cold-case units that look into unsolved homicides. The attorney general's unit is based at Pearl Harbor and works to consolidate state law-enforcement resources to close unsolved murder investigations. HPD's homicide division also devotes time to cold-case investigations.

Analysis of DNA evidence is a key element in the resolution of old and new criminal cases. Investigators rely heavily on DNA to solve most cold cases.

The attorney general's unit employs at least three retired HPD homicide detectives.

Reach Peter Boylan at pboylan@honoluluadvertiser.com.