PORTLAND, Maine (NEWS CENTER) -- A homeless man accused of stabbing and killing a man in a Walmart parking lot has plead not guilty to his murder charge.

Kenneth Briggs was charged with the murder of Roger Nelsen. Nelsen was found laying in a pool of blood in Falmouth Walmart parking lot back in August.

Briggs was not required to enter a plea during his initial court appearance and was ordered to have a mental evaluation. The evaluation has been completed and the results have been pending.

Briggs' attorney Molly Butler Bailey stated that she is not confident that Briggs is competent enough to understand the charge. He is being held without bail.