Authorities had previously identified Malvo as John Lee Malvo.

CNN: Killing in another Montgomery: Murder charges filed

Authorities say they believe the letter was written by either John Allen Williams, 41 -- also known as John Allen Muhammad -- or John Lee Malvo, 17, a Jamaican citizen, each charged October 25 with six counts of first-degree murder in Montgomery County, Maryland.

CNN: Letter found at shooting scene

MONTGOMERY, Alabama (CNN) -- A killing in Montogomery, Alabama, last month has led to the first murder charges to be filed against accused Washington-area snipers John Allen Muhammad and Lee Boyd Malvo, 17.

CNN: Killing in another Montgomery: Murder charges filed