Police in Brazil say this man's confessed to killing 39 people over three years.
Thiago Henrique Gomes da Rocha was arrested earlier this week.
The dead were mostly women and the homeless.
On Thursday, relatives of some victims gathered outside the police centre where da Rocha is being held.
(SOUNDBITE) (Portuguese) UNIDENTIFIED FAMILY MEMBER OF A MURDER VICTIM, SAYING:
"I'm a bit relieved. I know this pain will not go away. I know what he did will last forever."
da Rocha's lawyer says he's denied the charges.
(SOUNDBITE) (Portuguese) UNIDENTIFIED DEFENCE ATTORNEY, SAYING:
"(I want to see) the police investigation, to see the evidence they really have against him. I spoke with him yesterday and he denied the events to me."
Investigations are ongoing.