Edit Vanegas stood outside Nassau county criminal court, weeping openly.
But it appears Vanegas will be more than a spectator.
In his opening statement, Lacey's lawyer raised questions about whether Vanegas himself should have been a suspect in last February's deadly blaze.
"He was the last one in and the first one out that night," argued lawyer Christopher Cassar, pointing to the fact that Vanegas escaped the fire with his two sons.
"Vanegas had an abusive relationship with his wife, had been in and out of family court with her and for a time before the fire, had been living away from his family, with a girlfriend," added Cassar.
"My client did not start this fire," concluded Cassar.
Lacey was targeted by police, Cassar claimed, in a blatant rush to judgment.
But prosecutor Mike Canty told a different tale, alleging that Lacey, a probationary volunteer with the Lawrence-Cedarhurst fire department, used gas to ignite the fire on the steps leading to the Vanegas' second floor apartment.
Lacey's alleged motive - he wanted, said Canty, "to realize his dream of responding to a big fire and possibly be a hero."
"This case is sad and tragic but also criminal," said Canty, who argued that gasoline was later detected on Lacey's clothing.
"He never intended to kill these people," said prosecutor Canty.
"But something went horribly wrong."
Prosecutors will move forward without a prime piece of evidence.
Jurors won't be able to see what police say was Lacey's videotaped confession.
A county judge threw out the video last year, citing its poor audio quality and ruled that detectives can not testify about what was said during that interrogation.