A Seattle man was charged Friday in connection with a series of robberies and burglaries of four current and former professional athletes.

Earl Henderson Riley IV, 21, was charged with robbery in the first degree and several counts of burglary, according to the King County Prosecuting Attorney’s Office.

Prosecutors accused Riley of breaking into the homes of and stealing from Seattle Mariners pitcher Luis Castillo and center fielder Julio Rodriguez, former Seattle Seahawks cornerback Richard Sherman and Los Angeles Dodgers pitcher Blake Snell on different days this spring.

Riley allegedly stole upward of $300,000 worth of designer purses, high-end jewelry and luxury watches from the athletes’ homes, according to court documents shared with NBC News.

Authorities say Riley was a “ringleader” of the alleged crimes and suggested that officials are investigating others’ involvement.

“That doesn’t mean our work is finished,” Senior Deputy Prosecuting Attorney Gary Ernsdorff said. “We still want to go and identify everybody who was involved and see if there are additional people that we can have sufficient evidence to charge.”

Riley is being held in the King County Jail just outside of Seattle on $1 million bail. Prosecutors said the defendant was previously held in custody and released in February after pleading guilty as charged to three robbery counts.

It was not immediately clear if Riley had retained an attorney. His arraignment is scheduled for June 16.

The series of alleged crimes were among a wider slew of burglaries that victimized high-profile athletes in recent months.

Late last year, the homes of several athletes, including Kansas City Chiefs stars Patrick Mahomes and Travis Kelce and Milwaukee Bucks forward Bobby Portis, were burglarized. Seven men were arrested and charged in connection with the alleged burglaries in February.

In November, the NBA and NFL issued warnings to their players about the growing threat of organized burglary rings targeting high-profile athletes and other wealthy Americans.

The NBA memo, citing FBI intelligence, stated that the groups of criminals were using “advanced techniques” such as pre-surveillance, drones, signal-jamming devices and other cutting-edge technology.

This article was originally published on NBCNews.com