Double killer Jason Prentice, who stabbed to death a drinking pal and her friend, might have a mental disorder that makes him act in an aggressive way, a court heard.

Dr Susan Young told a Chelmsford Crown Court jury Prentice, of Ronald Park Avenue, Westcliff, was "over-emotional, moody and over-reactive".

Prentice, 30, has pleaded not guilty to murdering Jane Phipps, 24, and Steven Keys, 28, last June at their block of flats in London Road, Westcliff.

The court earlier heard Prentice allegedly murdered Miss Phipps after his estranged wife told him she was not prepared to put up with Miss Phipps' behaviour.

Neighbour Mr Keys was also found stabbed to death.

The jury has heard Prentice admits stabbing them but that he cannot remember anything about the attack because of black-outs suffered since childhood.

Dr Young, a clinical psychologist, told the court she spent more than eight hours with Prentice to try to establish his mental state.

She conducted a series of internationally-recognised tests, interviewed family members and read his school reports.

From her research she told the court he was "likely" to have attention deficit hyperactivity disorder.

She explained somebody with the disorder would "tend to behave in an aggressive way, tend not to get on with their peers, tend to be inattentive and to act without thinking of the consequences".

Dr Young added: "We often find they do not participate in social activities, they do not have many interests. The interests they do have are not constructive, like walking the streets.

"I think these problems had continued into adulthood."

Prentice's IQ was tested and the court heard that he scored "within the average range" for visual skills and "borderline" for verbal ability.

Dr Young said: "He's very volatile, a fast trigger to anger. He becomes infuriated and fluctuates into an angry state."

The trial continues.

Jason Prentice - has mental problems?

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