Taylor was shot during a break-in at his home in the Miami suburb of Palmetto Bay last week.
The Miami Herald quoted an attorney for one of the four men being held in the killing as saying a fifth suspect is being sought.
"We have confirmed it with multiple sources," said attorney Sawyer Smith, who is representing Jason Mitchell, 19.
Charged with felony murder, home invasion and burglary along with Mitchell are Eric Rivera, 17, Venjah Hunte, 20, and Charles Wardlow, 18.
They were arrested in Fort Myers, about 100 miles from Miami.
Taylor, who played safety for the Redskins, was shot Nov. 26 when he came upon intruders in his home. He was 24.