Abrego received extensive training at the General Francisco Morazán Military Academy in Honduras, the Western Hemisphere Institute for Security Cooperation (WHINSEC; formerly known as the School of the Americas) and attended the Officer's Staff Course conducted by the US Special Forces. Young Abrego returned to Panama to serve in the now defunct Panamanian Defense Forces under late General Manuel Noreiga. He was a member of the elite Batallon 2000 unit, which surrendered to US forces early into the United States invasion of Panama. Like many former Panamanian special forces officers, Abrego transitioned into law enforcement, sub-sequentially spending 22 years working for the National Police of Panama, including in riot control and anti-terrorism operations. Abrego also headed Panama's border patrol affairs prior to its separation from the National Police of Panama and establishment as an independent entity heavily funded by the United States.