A nearly 30-year Lowell Police veteran is accusing the department of resisting the promotion of minority officers to high-ranking positions in an effort to keep its leadership mostly white.

Sgt. Francisco Maldonado, 54, was recently bypassed for a promotion despite being the top candidate in line to receive the rank of lieutenant. A white officer, Sgt. Joseph Murray, received the promotion instead. Maldonado is appealing the decision with the state’s civil service commission.

“I think I haven’t been promoted because of the color of my skin,” Maldonado told GBH News in an exclusive interview this week.

Maldonado, who is Hispanic, began serving in the Lowell Police Department in 1996. He claims he has qualified but been passed up for promotions at least a half dozen times during his career in Lowell.

“This is a systematic system of holding minority people back,” he said. “You don't have three or four generations of the same last name white males without having to bypass or [perform] shenanigans on people that are in the way.”

According to the Lowell Police Department, 72% of its officers are white, 3% are Black, 7% are Asian, and 18% are Hispanic or Latino. Meanwhile, Census data shows the city's population overall is 58% white, 9% Black, 22% Asian, and 18% Hispanic or Latino.

The Lowell Police Department earlier this year launched a campaign to recruit more officers of color. And in July, the department announced nine promotions, including its first Hispanic officer to the rank of captain and its first Black officer to the rank of sergeant.

In an letter explaining the denied promotion for Maldonado earlier this month, Lowell City Manager Thomas A. Golden Jr. acknowledged that Maldonado was the top-placed candidate, but said the second-place candidate, Murray, was “uniquely qualified” to be promoted over him. Golden pointed to more than a dozen incidents that raised concerns about Maldonado’s leadership capabilities including being absent from court, causing an accident and “insubordination towards another officer.”

Golden did not respond to GBH News' request for comment on the matter this week.

In a response letter, Massachusetts Association of Minority Law Enforcement Officers President Jeffrey Lopes said the incidents amounted to “extremely minor infractions compared to other Lowell PD employees who have been promoted as recently as this year.” Lopes also noted that none of Maldonado’s incidents carried suspensions or punishment days.

Maldonado is also pursuing a complaint with the state’s discrimination commission over a separate, earlier promotion denial.