A Washington, D.C. police lieutenant who had held a visible role in outreach and in his union was arrested on charges tied to online contact with someone he believed to be a 15-year-old. The arrest in Harford County, Maryland led to criminal charges including sexual solicitation of a minor and two counts related to child pornography, and the officer was placed on administrative leave as investigators move forward.
Authorities say the suspect, Lt. Matthew Mahl, was taken into custody after an undercover operation that began online. The case centers on messages and explicit images exchanged over several weeks with a user in an online forum, and prosecutors say Mahl repeatedly acknowledged the person’s age.
Mahl, described in court papers as 47 years old, previously led MPD’s Gay & Lesbian Liaison Unit and had been elected to the department’s union leadership in 2016. Those roles put him in public-facing positions that carried responsibility for outreach and trust with vulnerable communities.
Prosecutors allege the contact began in a subreddit thread focused on young-adult dating and escalated into an exchange of sexually explicit material. Charging documents claim Mahl admitted multiple times that he believed the other party to be 15, and that the interactions lasted for roughly a month before the undercover meeting was arranged.
According to the affidavit, Mahl sent explicit photographs and messages and acknowledged the risks of exposure because of his badge and position. “I have it all to lose,” he allegedly wrote in the online conversation, a line prosecutors cited as showing his awareness of the stakes.
The arrest occurred after Mahl traveled to Harford County aiming to meet the person he believed was a minor; the “teenager” was actually an undercover police officer. Metropolitan Police Department officials said they were not aware of the investigation when the arrest took place and that MPD’s Internal Affairs Division will review any policy violations after the criminal inquiry finishes.
At a bail hearing prosecutors used blunt language, calling the defendant a “wolf in sheep’s clothing” as they argued to keep him detained. Judges ordered Mahl to remain in custody without bail while the case proceeds, citing the seriousness of the charges and the alleged conduct.
‘It really is a horrific tragedy when we think about the impact that this could have on young people.’
Local advocates weighed in, emphasizing the breach of trust these allegations represent. “These are individuals that the kids should be able to put their trust in. So it’s not just a tragedy, it really is a horrific tragedy when we think about the impact that this could have on young people trusting those that they really often need … for their own safety,” Turnaround Rape Crisis Center CEO Amanda Rodriguez said in a statement to reporters.
She added, “We need to hold folks in law enforcement and, again, in these other higher areas of authority to a level to ensure that that trust is always able to be there.” Her comments underline how cases involving alleged misconduct by uniformed officers resonate beyond the immediate criminal charges and touch on community confidence.
The department has promised to cooperate with prosecutors while also conducting its own review once the criminal work wraps up. Meanwhile, the criminal case will proceed in Maryland courts and could include additional investigative steps such as forensic analysis of devices and records from the online platform where the conversations took place.
Community leaders and victims’ advocates say the case is a reminder that online spaces can be weaponized against young people and that those in positions of authority must be held to the highest standards. As the legal process unfolds, questions about transparency, oversight, and how departments detect and respond to allegations will remain central to public concern.
