By CBS3 Staff

PHILADELPHIA (CBS) — Philadelphia police have identified the second suspect in the murder of 2-year-old Nikolette Rivera. Tavon Thomas, said to be in his 20s, was taken into custody Wednesday on unrelated charges and sources say he’s confessed to killing the toddler.

Officials believe Thomas was the one who pulled the trigger of the gun that killed Rivera.

Nikolette was killed Sunday afternoon when police say a gunman fired an AK-47 assault rifle into her family’s Kensington home on the 3300 block of Water Street.

On Tuesday night, Freddie Perez was arrested by Philadelphia police in Chester. He has been charged with murder and nine counts of attempted murder.

A makeshift memorial was made outside of the home where Nikolette was killed and today family members recently released videos on social media with sweet memories of their little girl.

The video shows Nikolette laughing while shopping for a Halloween costume.

Her family is heartbroken and says they would do anything to hear that laugh again.

Nikolette was in her mother’s arms when she was struck in the back of the head and killed.

Her 24-year-old mother was shot in the right side of her head and once in the back.

Investigators believe Thomas and Perez thought the man cleaning carpets inside the home was Rivera’s father who was in a dispute with the gunman over drugs.

“He was clearly targeting the house. The father was not at home at the time but that’s clearly where the beef was,” Acting Philadelphia Police Commissioner Christine Coulter said.

Police sources say Perez was driving a distinctive looking car while someone in the passenger seat started firing a rifle into the home. One of the gunmen is believed to have had a handgun, the other an AK-47.

A car linked to Perez was captured by a security camera a few blocks away from the deadly shooting scene over on Clearfield Street. That’s where two men inside the car were seen shooting up a parked car and leaving behind important ballistic evidence.

No one was hurt there, but it happened less than 10 minutes before Rivera was killed.

“From that video, we were able to get a very good description of the car,” Coulter said.

Authorities also say while security video showing the suspects’ car led them to Perez’s home, tips from the public helped them identify him.

CBS3’s Matt Petrillo contributed to this report.