A longtime Twin Cities girls volleyball coach has admitted in court to spending years sexually assaulting and pursuing numerous female players, using social media to entice his victims and video recording some of the encounters.

Dorian Christopher Barrs, 32, of Minnetonka pleaded guilty Monday in U.S. District Court in Minneapolis to two counts of producing child pornography in connection with his preying on the girls from October 2014 until March of this year.

The plea agreement lists 18 victims in all, ranging in age from 14 to 17 years old, with at least half of them he targeted while he was their coach.

All of the girls played for him at one time for either Maple Grove High School or the Minnesota Select or Minnesota Crossfire club teams in the Twin Cities.

Barrs remains held in the Sherburne County jail without bail ahead of sentencing, which has yet to be scheduled. The plea deal noted that federal guidelines call for a prison term of 60 years, with a minimum sentence of no less than 15 years.

At the same time, according to the plea deal, prosecutors have agreed to not seek a sentence longer than 35 years, while the defense indicated it won't push for a term shorter than 20 years.

Regardless of any guideline calculation or recommendation, federal judges have full discretion when sentencing defendants.

According to the plea agreement and a grand jury indictment from late July:

Barrs used SnapChat, text messaging and other social media and communication applications to engage female minor victims into sexual conversations. From there, he enticed and coerced the girls to produce child pornography and send him sexually explicit images and videos depicting them in sexual activity including with him at times.

The plea agreement noted that Barrs "often assumed the identity and SnapChat account of a minor victim ... in order to attempt to and knowingly employ, use, persuade, induce, entice and coerce minor victims ... into creating and sending him images and videos of themselves engaged in sexually explicit conduct." He then used that material to pursue still more victims.

A filing in May in Hennepin County District Court made by a sheriff's detective laid out further allegations against Barrs.

According to the search warrant application, which sought court permission to gather team rosters and employment data from the Minnesota Select's Osseo headquarters:

A 16-year-old girl said she won a spot two years ago on a Minnesota Select roster and became close to Barrs and another of her coaches. At the end of that first season, Barrs offered to coach her privately.

They quit meeting once she joined a different club team. However, the two kept in contact through SnapChat, and he directed her to add a woman to SnapChat because "I want her to be your new older sister."

The woman quickly turned the conversation, which "was normal" at the start, into increasingly sexual comments and asked whether the girl wanted to have sex with Barrs. The girl pushed back, but the woman persisted and asked the girl again more than 20 times.

The girl asked Barrs about the woman, and he said she was 20 years old and someone he formerly coached. The girl told him the woman made her uncomfortable, but Barrs responded by pursuing the girl for sex.

A law enforcement search of SnapChat confirmed the account the girl gave to investigators and also showed Barrs was in relationships with three women, ages 29, 20 and a 16-year-old volleyball player he coached at Maple Grove High School as of the May filing.