He made the comments referencing the Awayaso West Wuogon by-election, in which National Security Officials in mask stormed the election ground and fire multiple shots at the direction of the home of the opposition candidate.
“As we go to the polls in 2020, President Nana Akufo-Addo has a responsibility to secure the safety of all citizens and must resist the temptation to allow the use of violence to harm and intimidate innocent civilians as we observed last year during the Ayawaso West Wuogon by-election," Mr Mahama said in his new year message.
The former president pledged to work for peace and urged the president to do same.
"As a first step, I suggest he stops shielding the perpetrators of the violence at Ayawaso West Wuogon," he said.
"He must have them face the appropriate sanctions,” Mr Mahama charged.