The evidence was presented by prosecutors in the trial of Joshua Komisarjevsky, who faces a possible death sentence if convicted.
His co-defendant, Steven Hayes, was convicted last year of strangling Jennifer Hawke-Petit after taking her to a bank to get money and killing her two daughters, Hayley and Michaela. Hayes was sentenced to death.
Komisarjevsky admits to beating Hawke-Petit's husband, Dr. William Petit, with a bat and molesting his younger daughter after cutting off her clothes with scissors, but blames Hayes for the three killings.
Prosecutors also showed jurors photos of the girl's cut bra and scissors found in her room.
The Petit home in Cheshire was doused in gas and set on fire after the girls were tied to their beds. Petit was tied up as well, but managed to escape to a neighbor's house to get help.
Prosecutors showed jurors photos of a man getting gas at a local station in the Petits' car that they say was Hayes.
A dog trained to detect gas found spots believed to be accelerants on the floor of the girls' bedrooms, in the hallway and on a staircase, Connecticut State Police Sgt. Karen Gabianelli said.
Jurors also were shown photos of melted plastic containers that held the gas and the victims' charred clothes. They also saw knit hats with holes cut in them recovered at the scene authorities say the men wore.
Michaela's clothes had bleach stains, Gabianelli said. Hayes' attorney said during his trial that Komisarjevsky had poured bleach on her clothes to try to eliminate his DNA.
Authorities seized Michaela's purple cellphone from Komisarjevsky after he was arrested, Gabianelli said.
Komisarjevsky's attorneys brought up a photo of the basement where Petit was tied up to ask about a towel, pillows and a blanket that Komisarjevsky said he placed to make Petit more comfortable and to stop his bleeding. Gabianelli confirmed there were pillows and a blanket.
Hayes and Komisarjevsky have tried to blame each other for escalating the crime, but prosecutors say both men are responsible.