“The NFL continues to investigate an incident involving [Elliott], NFLPA sources and a source close to the Cowboys rookie told ESPN,” ESPN’s Adam Schefter reported Sunday. “One of the sources said the league is trying to be thorough in its investigation, and Elliott is aware of the league’s doggedness.”

NFL security representative Ed DuBois sent a letter to the department saying the league is “very aggressive in its investigation of this conduct,” per A.J. Perez of USA Today.

“[The woman] claims that Elliott abused her in February of 2016 in Aventura,” DuBois wrote. “She claims that she called the Aventura Police via 911 and that officers arrived but decided not to arrest Elliott.”

An ex-girlfriend accused Elliott of multiple counts of domestic violence. Police in Columbus, Ohio, declined to charge Elliott in September after investigating the woman’s allegations that she was abused over a five-day stretch in July.

The woman posted pictures on her Instagram account that she said depicted bruises caused by encounters with Elliott. The Columbus City Attorney’s Office cited “inconsistent information” in a statement as its reason for declining to press charges in that case, per USA Today:

After reviewing the totality of the evidence, the City Attorney’s Office, Prosecutor Division is declining to approve criminal charges in this matter for any of the (five) alleged incidents. This is primarily due to conflicting and inconsistent information across all incidents resulting in concern regarding the sufficiency of evidence to support the filing of criminal charges.

A Columbus city attorney told USA Today his department had no knowledge of the alleged Florida incident when investigating Elliott over the summer.

According to an incident report from February, the woman alleged Elliott struck her “left-upper chest” during an argument and pushed her against a wall, per Perez. Elliott told police the woman “became angry over a social media incident and upset because she was asked to leave his apartment, and go back to Ohio.”

She also alleged previous counts of domestic violence but did not report them. The woman did not file charges in Florida after police were unable to arrest Elliott because of conflicting stories and a lack of evidence.

Elliott has consistently denied all allegations.

Follow Tyler Conway (@jtylerconway) on Twitter.