RCMP Commissioner Bob Paulson says he plans to step away from his job as Canada’s top Mountie in June after a nearly four-decade career in law enforcement.

The announcement Monday comes as the force grapples with a number of serious internal issues.

Paulson, in his letter of resignation, acknowledged the RCMP has “serious challenges and work ahead,” highlighting “historical yet persistent harassment claims,” mental health issues among officers, and labour code charges related to the shooting of five Mounties in Moncton, among other challenges.

Resignation letter of RCMP Commissioner Bob Paulson:

After what will be almost 39 years of service, 32 in the RCMP and five and a half as Commissioner, the time has come for me to retire. My last day of work will be June 30, 2017 and I am excited to be able to focus on my family.

This will give the Government time to identify my replacement and we will no doubt hear more about that in due course.

In the meantime though, we have some challenges and work ahead of us.

We must try to resolve these historical yet persistent harassment claims;

We will continue to build, expand and improve our nascent mental health strategy to preserve and restore our employee’s mental and emotional wellness;

We must continue to improve our workplace for all of our employees by focusing on respect, inclusiveness, tolerance and diversity;

In April we will be tried on labour code charges arising from the murder of our colleagues in Moncton;

And of course I am committed to pursuing equitable pay and providing a modern labour relations framework for our employees.

No small list. These issues and those who follow them closely will make for a busy and challenging spring but we will -- as we do -- persevere in order that we can keep delivering on our primary mission -- keeping Canadians safe and secure.

As I said when I was first appointed Commissioner in 2011, it is a profound honour and a privilege to be able to serve in this great Force along side the good men and women who come to work each day and commit to this vital mission.

Here’s a look at some of the issues the new commissioner will face:

Sexual harassment controversy:

Federal court Judge Ann Marie McDonald certified a class action lawsuit last month involving as many 20,000 current and former officers who may have suffered gender-based discrimination and harassment on the job -- essentially all women who work for, or did work for, the RCMP starting in 1974.

Last October, Paulson delivered an abject apology to hundreds of current and former female officers and employees who were subjected to bullying, discrimination and harassment from fellow members.

“To all the women, I stand humbly before you today and solemnly offer our sincere apology,” an emotional Paulson told a news conference in Ottawa.

“You came to the RCMP wanting to personally contribute to your community and we failed you. We hurt you. For that, I am truly sorry.”

Ottawa has set aside about $100 million to compensate victims. The RCMP agreed to address systemic issues of gender discrimination.

Mental health:

In 2014, the force formally delved into the issues of suicide and mental health within its ranks, revealing some 32 serving and retired members have taken their lives since 2006.

A five-year mental health initiative launched by then- assistant RCMP commissioner Gilles Moreau found significant stigma associated with seeking help for mental health issues, and aimed to encourage officers to seek assistance if they are in need.

“I think it's a first step -- it's very focused on education and stigma reduction, which I think is needed,” he told The Canadian Press in 2014. “But I think there are huge gaps in the strategy in areas in developing resilience, treating trauma and conducting research to determine the extent of the rates of PTSD and other mental health concerns in RCMP employees.”

RCMP labour code & union talks

RCMP officers won the right to organize a union two years ago, but a collective bargaining bill remains in limbo.

The Liberal government tabled a bill to create a new labour relations regime for RCMP members and reservists last March. The legislation allows for collective bargaining and independent, binding arbitration to resolve disputes, but no right to strike.

Currently, RCMP officers have voluntary associations funded by members, which work with management to establish pay and benefits. However, top management has the final say.

Senators sent bill C-7 back to the House of Commons in June after removing a list of contentious issues that had been excluded from collective bargaining.

Moncton shootings

The RCMP is facing a lawsuit from Employment and Social Development Canada regarding its response to the 2014 shooting rampage in Moncton, N.B. that left three officers dead.

The federal labour market watchdog alleges RCMP members and supervisors were not provided with appropriate information, training, and equipment to handle the active shooter event.

Gunman Justin Bourque shot and killed constables Doug Larche, Fabrice Gevaudan and Dave Ross, and wounded constables Eric Dubois and Darlene Goguen with a semi-automatic rifle on June 4, 2014 during a manhunt that lasted roughly 30 hours.

The trial is set to begin on April 18.

With files from The Canadian Press