Welsh was kidnapped last week while having coffee at a friend's home and later found dead in a wooded area in Bristol, about 10 miles away. If convicted, Williams could face the death penalty.
Williams was already being held on charges of attempted murder, kidnapping and burglary connected with injuries suffered by Welsh's friend, homeowner Carol Larese, 66. She was shot during the attack but survived by playing dead, police said.
The court appointed a public defender, David Smith, to represent Williams, but the judge told attorneys and parties in the case not to speak outside the courtroom to ensure a fair trial.
According to a warrant, Williams told police he was sleeping in an unlocked car in Larese's neighborhood around 9 a.m. March 30 when he saw Welsh arrive for coffee.
Police said he followed her in through an unlocked door and told the women he wanted money and a car. They say he decided he had to shoot the women because they would be able to recognize him.
Williams was arrested after crashing Welsh's car some 25 miles away after a police chase about five hours after the home invasion, authorities said.
He is a convicted sex offender who had been released four weeks earlier from prison after finishing an eight-year sentence for sexually assaulting a 5-year-old girl he knew. He was living in a Hartford homeless shelter.
