Official: No evidence linking individual to Flight 370's disappearance

Malaysia's police chief Khalid Abu Bakar answers questions during a press conference at a hotel near Kuala Lumpur International Airport in Sepang on March 16, 2014.

There remains no tangible evidence that links an individual to the disappearance of Malaysia Airlines Flight 370, a senior Malaysian law enforcement official told CBS News on Friday.

The official said the police investigation into Flight 370 was officially classified as a criminal investigation on March 15 after government officials announced that the disabling of the communications (ACARS) system and the changing path of the plane were consistent with a deliberate action by someone on the plane.

The official said while at the moment the passengers on MH370 have been "cleared," meaning their background checks have not revealed anything to raise alarm, that does not mean that the focus of the investigation has shifted towards the crew and pilots. According to the official, it means more investigation remains.

According to the official, as part of the investigation, police are also talking to everyone involved in the handling and consignment of the cargo on MH370. The cargo manifest for MH370 has so far not been made public. A request from CBS News for that document is pending.

Two days ago, Malaysia's national police chief Khalid Abu Bakar said that all 227 passengers have been cleared of any involvement, but he admitted that what happened onboard the plane may never be known.

Suspicion has fallen on pilot Zaharie Ahmad Shah and co-pilot Fariq Abdul Hamid, and investigators have now begun interviewing the families of the flight crew.

Jacquie Gonzales' husband, Patrick Gomez, was the chief steward on Flight 370.

She told CBS News that Malaysian police went to her home Tuesday and asked about Patrick's bank accounts, insurance and even his hobbies.

But the crucial missing link for investigators is the plane's wreckage - and especially its two black boxes, or flight recorders.

Crews searching for the missing jet launched a targeted underwater hunt on Friday for the plane's black boxes along a stretch of remote ocean, with just days left before the devices' batteries are expected to run out.