Nikki joined Merseyside Police in 1988 and was posted to various areas of Merseyside.  She successfully introduced the process of targeting Organised Crime Groups within Merseyside and worked her way through the ranks. 
Nikki joined South Wales Police in 2014 as Assistant Chief Constable, Specialist Crime and Tarian (ROCU) and took the Chief Officer lead role on numerous Counter Terrorism, Drug, Cyber and International CSE operations. 
Nikki led on protecting vulnerable people and fight against Child Sexual Exploitation and Violence Against Women. She was instrumental in bringing the Multi Agency Safeguarding Hub into being and developing the ‘All Wales CSE Action Plan’. 
In 2015, Nikki returned to Merseyside as Assistant Chief Constable, Investigation, Intelligence, Serious and Organised Crime and TITAN ROCU.  
In 2017, Nikki was promoted to Director of Investigations in the NCA. She has responsibility for the management of NCA Investigations including; specialist investigations, economic crime, serious crime review, CSAE and the armed operations unit. 
Nikki continues as Platinum Commander on some of the most serious and high profile investigations in the country and continues to take the lead role in firearms operations throughout the UK.
In 2018, Nikki became NCA Lead for County Lines and the National County Lines Coordination Centre and works closely with DAC Duncan Ball to tackle high level criminals exploiting vulnerable people and children to transport drugs across the UK. Together they represented law enforcement at a Home Affairs Committee Enquiry in January 2019 and continue to work closely together to tackle County Lines from a law enforcement perspective.