One of the men accused of the Washington sniper killings has been found guilty of murder, terrorism, conspiracy and a firearms charge.
Muhammad denied the charges
John Allen Muhammad, 42, now may face the death penalty.
He was convicted of shooting dead Dean Meyers at a petrol station in Manassas, Virginia, on 9 October 2002, and murdering "at least one other person".
He may also face other charges relating to the killings, which left 10 dead and three wounded.
Along with his alleged accomplice, 18-year-old Lee Boyd Malvo, he is also accused of three murders and three counts of wounding across the United States.
Mr Malvo is on trial separately.
Death penalty urged
After a three-week trial, the jury at a court in Virginia Beach, Virginia, deliberated for more than six hours before returning unanimous guilty verdicts on all four charges against Muhammad. Two of the jury members were crying as the decision was read out.
The terrorism charge was brought under a new law enacted by Virginia following the devastating suicide attacks of 11 September 2001, on New York and Washington.
The BBC's Adam Brookes, in Washington, says the jury and court will now deliberate on whether he should receive the death penalty.
Malvo: Insanity plea
The jury is expected to decide on this within the next few days.
Relatives of the victims have welcomed the verdict, and some have urged the imposition of the death penalty. One said the case should serve to highlight the level of gun violence in the United States.
Bob Meyers, the brother of the victim at the heart of the trial, said: "I believe that capital punishment is an appropriate response in certain crimes and I must say that I can't think of too many more heinous crimes than this one."
During the trial, prosecutors portrayed Muhammad as a cold-blooded killer who trained Mr Malvo as an expert sniper before using a specially modified car to engage in a murder spree that terrorised the Washington area.
One prosecutor described Muhammad as the type of man who could pat you on the back, then cut your throat.
They produced a rifle they said was used in the shootings, as well as a car with a hole in the boot through which a sniper could fire.
The pair carried out the killings, prosecutors said, in an attempt to extort a $10m ransom from the US Government.
Muhammad's court-appointed lawyers - who were at one point dismissed by their client before being re-appointed by him - argued that the case against him was circumstantial.
They questioned the authority of expert
witnesses who testified about sniper technique and ballistic
evidence linking Muhammad to the murder weapon.
Another jury in nearby Chesapeake, Virginia, has begun hearing testimony in the trial of Mr Malvo.
He is accused of murdering FBI analyst Linda Franklin, who was shot dead on 14 October 2002 in Falls Church, Virginia.
Mr Malvo's lawyers have told jurors they will not suggest that the authorities have the wrong man, but they contend that their client is innocent by reason of insanity.
They say he was brainwashed by Muhammad, whom he
looked up to as a father figure.
Mr Malvo could also face the death penalty if convicted, despite being aged 17 at the time of his alleged crimes.