Dead grandma's banking slip changed

A banking slip for the account of a slain Queensland grandmother was altered to boost the withdrawal amount by $5000, a court has heard.

Steven Mark John Fennell, 56, has pleaded not guilty to the murder of Liselotte Watson on Macleay Island, in Moreton Bay, in November 2012.

A Supreme Court jury was shown on Tuesday a series of banking slips he used to make authorised withdrawals for the elderly woman on the mainland and was told by a handwriting expert it appeared $3000 had been changed to $8000 on one.

Forensic document examiner Somapala Hettiarachi said three strokes had been made to produce the resulting figure but it couldn't be said in which order the strokes were done.

The court also heard from Christine Randall, who said she would see Fennell placing bets at the local pub she worked at two to three times a week.

The jury has already heard allegations the widow was attacked in her bed before her body was found on the bedroom floor on November 13.

On the opening day of the trial, crown prosecutor Glen Cash alleged Mrs Watson had been brutally and callously murdered by Fennell, most likely in an effort to cover up financial misdeeds.

The trial before Justice Martin Daubney continues.